Are we making good use of our public resources? The false-positive rate of screening by fundus photography for diabetic macular oedema.

INTRODUCTION: A large proportion of patients diagnosed with diabetic maculopathy using fundus photography and hence referred to specialist clinics following the current screening guidelines adopted in Hong Kong and United Kingdom are found to be false-positive, implying that they did not have macular oedema. This study aimed to evaluate the false-positive rate of diabetic maculopathy screening using the objective optical coherence tomography scan. METHODS: This was a cross-sectional observational study. Consecutive diabetic patients from the Hong Kong West Cluster Diabetic Retinopathy Screening Programme with fundus photographs graded R1M1 were recruited between October 2011 and June 2013. Spectral-domain optical coherence tomography imaging was performed. Central macular thickness of ≥300 µm and/or the presence of optical coherence tomography signs of diabetic macular oedema were used to define the presence of diabetic macular oedema. Patients with conditions other than diabetes that might affect macular thickness were excluded. The mean central macular thickness in various subgroups of R1M1 patients was calculated and the proportion of subjects with central macular thickness of ≥300 µm was used to assess the false-positive rate of this screening strategy. RESULTS: A total of 491 patients were recruited during the study period. Of the 352 who were eligible for analysis, 44.0%, 17.0%, and 38.9% were graded as M1 due to the presence of foveal 'haemorrhages', 'exudates', or 'haemorrhages and exudates', respectively. The mean (±standard deviation) central macular thickness was 265.1±55.4 µm. Only 13.4% (95% confidence interval, 9.8%-17.0%) of eyes had a central macular thickness of ≥300 µm, and 42.9% (95% confidence interval, 37.7%-48.1%) of eyes had at least one optical coherence tomography sign of diabetic macular oedema. For patients with retinal haemorrhages only, 9.0% (95% confidence interval, 4.5%-13.5%) had a central macular thickness of ≥300 µm; 23.2% (95% confidence interval, 16.6%-29.9%) had at least one optical coherence tomography sign of diabetic macular oedema. The false-positive rate of the current screening strategy for diabetic macular oedema was 86.6%. CONCLUSION: The high false-positive rate of the current diabetic macular oedema screening adopted by the United Kingdom and Hong Kong may lead to unnecessary psychological stress for patients and place a financial burden on the health care system. A better way of screening is urgently needed. Performing additional spectral-domain optical coherence tomography scans on selected patients fulfils this need.

Dietary exposure to organochlorine pesticide residues of the Hong Kong adult population from a total diet study.

Dietary exposure of the Hong Kong adult population to organochlorine pesticide (OCP) residues was estimated using a total diet study (TDS) approach. OCPs listed under the Stockholm Convention as persistent organic pollutants (POPs) including, aldrin, dieldrin, chlordane, chlordecone, dichlorodiphenyltricholroethane (DDT), endosulfan, endrin, heptachlor, hexachlorobenzene (HCB), α-hexachlorocyclohexanes (HCH), ß-HCH, lindane, mirex, pentachlorobenzene and toxaphene, were studied. Out of 600 composite samples, 55% contained one or more OCP residues at detectable levels. The most commonly detected OCP was DDT (32% of all composite samples), followed by HCB (30%) and endosulfan (22%). The lower- and upper-bound mean exposure estimates of OCP residues ranged from 0% to 0.5% and were 0.1-8.4% of their respective health-based guidance values (HBGVs). The lower- and upper-bound 95th percentile exposure estimates ranged from 0% to 1.2% and were 0.1-13.6% of their respective HBGVs. This indicated that dietary exposures to the OCP residues analysed would be unlikely to pose unacceptable health risks to Hong Kong adults.

Dietary exposures to eight metallic contaminants of the Hong Kong adult population from a total diet study.

Dietary exposures to eight metallic contaminants, aluminium (Al), antimony (Sb), cadmium (Cd), lead (Pb), methylmercury (MeHg), nickel (Ni), tin (Sn) and vanadium (V), of the Hong Kong adult population were estimated using the total diet study (TDS) approach. The estimated mean exposures of Al (0.60 mg kg(-1) bw week(-1)), Sb (0.016-0.039 µg kg(-1) bw day(-1)), Cd (8.3 µg kg(-1) bw month(-1)), Pb (0.21 µg kg(-1) bw day(-1)), MeHg (0.74 µg kg(-1) bw week(-1)), Ni (3.1 µg kg(-1) bw day(-1)), Sn (0.029-0.031 mg kg(-1) bw week(-1)) and V (0.13 µg kg(-1) bw day(-1)) were well below the relevant health-based guidance values (HBGVs) where available. However, dietary exposures to MeHg of women aged 20-49 years (child-bearing age) accounted for 150% of the provisional tolerable weekly intake (PTWI) and to Al and Cd of some high consumers were found exceeding or approaching the HBGVs. The major food contributors of MeHg were fish and seafood (90%), of Al were non-alcoholic beverages including tea (33%), and of Cd were vegetables (36%). MeHg exposure during pregnancy was a public health concern in Hong Kong due to potential health risks to the foetus. Results suggest that there is a need to continue monitoring the exposures to metallic contaminants, especially Al, Cd and MeHg, of the Hong Kong population.

Application of transport phenomena analysis technique to cerebrospinal fluid.

The study of hydrocephalus and the modeling of cerebrospinal fluid flow have proceeded in the past using mathematical analysis that was very capable of prediction phenomenonologically but not well in physiologic parameters. In this paper, the basis of fluid dynamics at the physiologic state is explained using first established equations of transport phenomenon. Then, microscopic and molecular level techniques of modeling are described using porous media theory and chemical kinetic theory and then applied to cerebrospinal fluid (CSF) dynamics. Using techniques of transport analysis allows the field of cerebrospinal fluid dynamics to approach the level of sophistication of urine and blood transport. Concepts such as intracellular and intercellular pathways, compartmentalization, and tortuosity are associated with quantifiable parameters that are relevant to the anatomy and physiology of cerebrospinal fluid transport. The engineering field of transport phenomenon is rich and steeped in architectural, aeronautical, nautical, and more recently biological history. This paper summarizes and reviews the approaches that have been taken in the field of engineering and applies it to CSF flow.

The characterization of arachnoid cell transport II: paracellular transport and blood-cerebrospinal fluid barrier formation.

We used an immortalized arachnoid cell line to test the arachnoid barrier properties and paracellular transport. The permeabilities of urea, mannitol, and inulin through monolayers were 2.9 ± 1.1 × 10(-6), 0.8 ± .18 × 10(-6), 1.0 ± .29 × 10(-6)cm/s. Size differential permeability testing with dextran clarified the arachnoidal blood-cerebrospinal fluid (CSF) barrier limit and established a rate of transcellular transport to be about two orders of magnitude slower than paracellular transport in a polyester membrane diffusion chamber. The theoretical pore size for paracellular space is 11Å and the occupancy to length ratio is 0.8 and 0.72 cm(-1) for urea and mannitol respectively. The permeability of the monolayer was not significantly different from apical to basal and vice versa. Gap junctions may have a role in contributing to barrier formation. Although the upregulation of claudin by dexamethasone did not significantly alter paracellular transport, increasing intracellular cAMP decreased mannitol permeability. Calcium modulated paracellular transport, but only selectively with the ion chelator, EDTA, and with disruption of intracellular stores. The blood-CSF barrier at the arachnoid is anatomically and physiologically different from the vascular-based blood-brain barrier, but is similarly subject to modulation. We describe the basic paracellular transport characteristics of this CSF "sink" of the brain which will allow for a better description of mass and constitutive balance within the intracranial compartment.

Development and validation of a method for determination of residues of 15 pyrethroids and two metabolites of dithiocarbamates in foods by ultra-performance liquid chromatography-tandem mass spectrometry.

This paper reports a novel approach for the detection, confirmation, and quantification of 15 selected pyrethroid pesticides, including pyrethins, and two metabolites of dithiocarbamates in foods by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure that combines isolation of the pesticides and sample cleanup in a single step. Analysis of pyrethroids and dithiocarbamate metabolites was performed by UPLC-MS-MS operated with electrospray and atmospheric pressure chemical ionization, respectively. Two specific precursor-product ion transitions were acquired per target compound in multiple reaction monitoring (MRM) mode. Such acquisition achieved the minimum number of identification points according to European Commission (EC) document no. SANCO/10684/2009, thus fulfilling the EC point system requirement for identification of contaminants in samples. The method was validated with a variety of food samples. Calibration curves were linear and covered from 1 to 800 µg kg(-1) in the sample for all target compounds. Average recoveries, measured at mass fractions of 10 and 100 µg kg(-1) for pyrethroids and 5 and 50 µg kg(-1) for dithiocarbamate metabolites, were in the range of 70-120% for all target compounds with relative standard deviations below 20%. Method limits of quantification (MLOQ) were 10 µg kg(-1) and 5 µg kg(-1) for pyrethroids and dithiocarbamate metabolites, respectively. The method has been successfully applied to the analysis of 600 food samples in the course of the first Hong Kong total diet study with pyrethroids and metabolites of dithiocarbamates being the pesticides determined.

A qualitative study on HPV vaccination from a nursing perspective in Hong Kong.

OBJECTIVE: To identify the perception on human papillomavirus (HPV) vaccination among female nursing students in Hong Kong. DATA SOURCES: Data were collected through focus group discussions and semi-structured in-depth interviews. All participants (n=28) were female nursing students of a university in Hong Kong. Tape recordings of individual interviews and focus group discussions were transcribed verbatim in Chinese, translated into English, and analyzed according to Colaizzi's phenomenological analysis. STUDY DESIGN: Four major themes emerged from the data: nursing students' understanding about HPV vaccine, nursing students' attitude on HPV vaccine, nursing students' perspective on HPV vaccination promotion, and nursing role on HPV vaccination. CONCLUSIONS: Government should take initiative in promotion with vaccine suppliers. The awareness and knowledge of HPV and HPV vaccination among women should be increased in order to raise the positive attitude of women towards HPV vaccination and prevention of cervical cancer. Health professionals should work together on HPV promotion among women and increase the HPV vaccination rates. Moreover, further studies regarding attitude and awareness of HPV vaccination among women in different age groups are needed in order to identify more associated factors affecting their perceptions towards HPV vaccination.

Endoscopic carpal tunnel release: experience of surgical outcome in a Chinese population.

OBJECTIVE: To review the outcomes of endoscopic carpal tunnel release in a Hong Kong public hospital and identify any predictive factors. DESIGN: Retrospective study. SETTING: Regional hospital with a hand surgery service, Hong Kong. PATIENTS: Between January 2001 and December 2007, records of 145 patients (160 carpal tunnel syndromes) having endoscopic release were reviewed. Five major symptom domains (pain, numbness, nocturnal awakening, weakness, and clumsiness) before and after the operation were scrutinised. Functional status was assessed by grading key pinch and hand grip, as well as complications. INTERVENTION: Endoscopic carpal tunnel release using the modified Chow's extrabursal technique under intravenous anaesthesia. RESULTS: After the 160 procedures performed, 124 (78%) and 132 (83%) of them revealed improvement in terms of numbness and nocturnal awakening, respectively. Also, there were significant improvements in terms of average functional grading of pinch power and grip power. No serious complications due to the surgery were encountered. CONCLUSIONS: Experience using the Chow's two-portal endoscopic technique for the treatment of carpal tunnel syndrome in the Chinese population was encouraging. It was a safe and effective method for treating carpal tunnel syndrome. We advocate endoscopic surgical intervention for patients with refractory relief of symptoms following conservative management.

Seasonal and spatial variation of solvent extractable organic compounds in fine suspended particulate matter in Hong Kong.

The results of a 12-month study of more than 100 solvent extractable organic compounds (SEOC) in particulate matter (PM) less than or equal to 2.5 microm (PM2.5) collected at three air monitoring stations located at roadside, urban, and rural sites in Hong Kong are reported. The total yield of SEOC that accounts for approximately 8-18% of organic carbon (OC) determined by a thermal optical transmittance method was 125-2060 ng/m3, which included 14.6-128 ng/m3 resolved aliphatic hydrocarbons, 39.4-1380 ng/m3 unresolved complex mixtures, 0.6-17.2 ng/m3 polycyclic aromatic hydrocarbons, 41.6-520 ng/m3 fatty acids, and < 0.1-12.1 ng/m3 alkanols. Distinct seasonal variations (summer/winter differences) were observed with higher concentrations of the total and each class of SEOC in the winter and lower concentrations in the summer. Spatial variations are also obvious, with the roadside samples having the highest concentrations of SEOC and the rural samples having the lowest concentrations in all seasons. Characteristic ratios of petroleum hydrocarbons, such as carbon preference index, unresolved to resolved components, and carbon number with maximum concentration, suggest that PM2.5 carbon in Hong Kong originates from both biogenic and anthropogenic sources. The proportion of SEOC in PM2.5 from anthropogenic sources is estimated.

The detection of small relative simulated field defects using multifocal VEPs.

INTRODUCTION: The multifocal visual-evoked potential (mfVEP) has been widely used in the study of diseases of the visual system. However, the sensitivity of the mfVEP in the objective detection of relative field defects has not been determined. This study investigates variations in mfVEP responses while simulating relative field defects by using different luminous transmission masks [neutral density (ND) filters] on the stimulus pattern. METHODS: Simulated relative field defects with four different luminous transmissions were obtained by using 0.2, 0.4, 0.6, and 0.8 ND filters, 5 degrees in size, at two different retinal eccentricities (10 and 16 degrees) on a standard mfVEP dartboard stimulus. Eleven normal subjects were recruited for mfVEP measurements. The response amplitudes and latencies of the N1 and P1 of the mfVEP, with and without small simulated relative field defects, were compared. RESULTS: The mfVEP amplitudes of N1 and P1 decreased substantially when 0.6 and 0.8 ND filters were introduced. The effects were similar at both the 10- and 16-degree eccentricities but there was no change in latency with simulated field defects at either location. CONCLUSIONS: The mfVEP can detect a simulated relative field defect 5 degrees in size starting with 0.6 log unit reduction in luminance at both 10-degree and 16-degree eccentricities. This illustrates that the sensitivity of the mfVEP measurement is nearly comparable with that of the Humphrey Visual Field Analyser.

Distribution of polycyclic aromatic hydrocarbons in the atmosphere of Hong Kong.

This paper reports the monitoring results of eleven polycyclic aromatic hydrocarbons (PAHs), four to six-ring, at two urban sites-Central & Western (CW) and Tsuen Wan (TW) in Hong Kong from January to December 2000; and the findings of a study conducted in 2001 of the partitioning of the gaseous and particulate phases of PAHs. The sum of the eleven PAHs under study (sigmaPAHs) was found to range from 6.46 to 38.8 ng m(-3). The annual mean levels at 12.2 ng m(-3) and 15.8 ng m(-3) for CW and TW respectively are comparable to those recorded for the previous two years and are also within the reported ranges for other metropolitan cities in the Asia Pacific region. Amongst the selected eleven PAHs, fluoranthene and pyrene were the two most abundant found in the urban atmosphere of Hong Kong during the study period accounting for approximately 80%, of the total PAHs. The ratios of benzo(a)pyrene to benzo(g,h,i)perylene (BaP/BghiP) and indeno(1,2,3-cd)pyrene to benzo(g,h,i)perylene (IDP/BghiP) indicate that diesel and gasoline vehicular exhausts were the predominant local emission sources of PAHs. Seasonal variations with high winter to summer ratios for each of the individual PAHs (CW: 1.6-16.7 and TW: 0.82-8.2) and for sigmaPAHs (CW: 1.9 and TW: 1.8) and a spatial variation of BaP amongst the air monitoring stations are noted. Results of correlation studies illustrate that local meteorological conditions such as ambient temperature, solar radiation, wind speed and wind direction have significant impact on the concentrations of atmospheric PAHs accounting for the observed seasonal variations. A snapshot comparison of the concentrations of PAHs at four sites including a roadside site, a rural site and the two regular urban sites CW and TW was also performed using the profiles of PAHs recorded on two particulate episode days in March 2000.

Atorvastatin lowers C-reactive protein and improves endothelium-dependent vasodilation in type 2 diabetes mellitus.

Endothelial dysfunction is frequently found in diabetic subjects. This study was performed to investigate whether atorvastatin therapy was able to reverse endothelial dysfunction in type 2 diabetes and, if so, whether the effect was due to its antiinflammatory action. Eighty patients (baseline low density lipoprotein, 4.37 +/- 0.71 mmol/liter) were randomized to atorvastatin (10 mg daily for 3 months, followed by 20 mg daily for 3 months) or placebo in a double blind study. Endothelial function was assessed by high resolution vascular ultrasound, and high sensitivity C-reactive protein (CRP) was assessed by immunoturbidimetric assay. Diabetic patients had higher CRP (P < 0.01) than matched nondiabetic controls, and both endothelium-dependent and independent vasodilation were impaired (P < 0.01). Atorvastatin (10 and 20 mg) lowered plasma cholesterol by 32.9% and 38.0%, triglyceride by 15.4% and 23.1%, and low density lipoprotein by 43.4% and 50.1%, respectively. At 6 months, plasma CRP decreased in the atorvastatin group compared with baseline (P < 0.05). Endothelium-dependent vasodilation improved in the atorvastatin group compared with the placebo group (P < 0.05). The percent change in endothelium-dependent vasodilation at 6 months correlated with the percent change in CRP (r = -0.44; P < 0.05), but not with changes in plasma lipids. In conclusion, treatment with atorvastatin in type 2 diabetes led to a significant improvement in endothelium-dependent vasodilation, which might be partly related to its anti-inflammatory effect.

Ultrasonographic analysis of bladder tumors.

To analyze the ultrasonographic features of bladder tumors during transabdominal ultrasonography. Ultrasonograms of consecutive patients diagnosed to have bladder tumors from August 1992 to May 1999 were reviewed retrospectively and correlated with the final histological diagnoses. Various features, including the location, size, multiplicity, shape, surface and presence of calcification, of the bladder tumors were analyzed. Of 109 patients reviewed, 104 had transitional cell carcinoma, 3 adenocarcinoma, 1 carcinosarcoma and 1 prostatic carcinoma. A total of 130 tumors (including 13 multifocal tumors) were detected with 30 (27.5%) patients having more than one tumor in the bladder. Tumor size ranged from 0.5 to 9.7 cm (mean 2.7 cm). The tumor involved the trigone (63, 48.5%), lateral wall (32, 24.6%), posterior wall (17, 13.1%), anterior wall (5, 3.8%) or was multifocal (13, 10%). Sixty-seven (51.5%) tumors were polypoidal, 47 (36.2%) were sessile and 16 (12.3%) plaque-like. The surface was regular in 50 (38.5%) tumors and irregular in 80 (61.5%) tumors. Calcified foci were noted in 54 (41.5%) tumors. There was no statistically significant correlation between ultrasonographic features. The most common appearance is a polypoid lesion arising from the trigone, but there was much variation in the ultrasonographic features of bladder tumors.

Low-valent chemistry of cobalt amide. Synthesis and structural characterization of cobalt(II) amido, aryloxide, and thiolate compounds.

The binuclear cobalt(II) amide complex [(CoL2)2-(TMEDA)] (1) [L = N(Si(t)BuMe2)(2-C5H3N-6-Me); TMEDA = Me2NCH2CH2NMe2] has been synthesized by the reaction of anhydrous CoCl2 with 2 equiv of [Li(L)(TMEDA)]. X-ray crystallography revealed that complex 1 consists of two [CoL2] units linked by one TMEDA ligand molecule, which binds in an unusual N,N'-bridging mode. Protolysis of 1 with the bulky phenol Ar(Me)OH (Ar(Me) = 2,6-(t)Bu2-4-MeC6H2) and thiophenol ArSH (Ar = 2,4,6-(t)Bu3C6H2) gives the neutral monomeric cobalt(II) bis(aryloxide) [Co(OAr(Me))2(TMEDA)] (2) and dithiolate [Co(SAr)2(TMEDA)] (3), respectively. Complexes 1-3 have been characterized by mass spectrometry, microanalysis, magnetic moment, and melting-point measurements, in addition to X-ray crystallography.

Intra-operative MRI-guided approaches to the pediatric posterior fossa tumors.

INTRODUCTION: The posterior fossa in a child poses a considerable challenge to the neurosurgeon. MRI-guided surgery allows for real time interaction between imaging and the neurosurgeon, not permitted by frameless stereotaxy, and with higher resolution than ultrasound or CT. MATERIALS AND METHODS: The University of Minnesota 1.5 T Phillips interventional MRI was used. From 1997 to 2000, nine posterior fossa intraoperative magnet cases out of eleven were pediatric. The mean age was 6.4 years and the median age 7. Seven midline craniotomies were performed, of which three were re-operations. Two were burr hole placements, one for cyst aspiration and P32 instillation, and the other for tumor biopsy. RESULTS: Two tumors were predominantly in the fourth ventricle, four in the cerebellum, two in the brainstem, and one in the prepontine cystern. Four tumors were juvenile pilocytic astrocytomas, two were anaplastic astrocytomas, and one each was ependymoma, craniopharyngioma cyst, and medulloblastoma. Four patients had complete radiologic resection. Two had maximal resections limited by vital structures. P32 instillation and tumor biopsy were done in a single pass. Follow-up ranged from 3 months to 1.4 years. The cyst that was aspirated and had P32 instillation remains absent. The two mortalities were in the patients with medulloblastoma and anaplastic astrocytoma. There were no intra-operative mortalities. The other patient with anaplastic astrocytoma progressed. The remainder had stable imaging. CONCLUSION: MRI-guided surgery results in improved resection imaging and real-time needle guidance in tumor operations. Its value could lie in low-grade lesions, where maximal resection is most beneficial.

Syntheses, photophysics, and photochemistry of trinuclear copper(I) thiolate and hexanuclear copper(I) selenolate complexes: X-ray crystal structures of [Cu(6)(mu-dppm)4(mu(3)-SePh)4](BF(4))2 and [Cu(6)(mu-(Ph(2)P)(2)NH(4))(mu(3)-SePh)4](BF(4)2.

A series of trinuclear copper(I) thiolate complexes, [Cu(3)(mu-dppm)(3)(mu(3)-SR)(2)]BF(4) (R = C(6)H(4)Cl-4, C(6)H(4)CH(3)-4, C(6)H(4)OCH(3)-4, C(6)H(4)(OCH(3))(2)-3,4, C(6)H(4)-benzo-15-crown-5, or (t)()Bu), [Cu(3)(mu-dppm)(3)(mu(3)-S(t)()Bu)](BF(4))(2), and [Cu(3)(mu-dppm)(3)(mu(3)-SR)(mu(3)-Cl)]BF(4) (R = C(6)H(4)CH(3)-4, C(6)H(4)(t)()Bu-4, or C(6)H(4)(CH(3))(3)-2,4,6) and two hexanuclear copper(I) selenolate complexes, [Cu(6)(mu-P(wedge)P)(4)(mu(3)-SePh)(4)](BF(4))(2) (P(wedge)P = dppm, (Ph(2)P)(2)NH), have been synthesized, and their photophysical properties have been studied. The X-ray crystal structures of both copper(I) selenolate complexes have been determined. These complexes have been shown to exhibit long-lived low-energy emission in solution, attributed to an excited state of predominantly ligand-to-metal charge-transfer [chalcogenolate to copper(I)] origin.

Reversal of increased intracranial pressure with removal of a torcular epidermoid: case report.

OBJECTIVE AND IMPORTANCE: Venous obstruction has been postulated as a cause of increased intracranial pressure, but it has been documented rarely. We present a case of obstruction of the torcula by a slow-growing epidermoid. The tumor caused increased intracranial pressure, which was relieved when it was excised. In addition, the torcular epidermoid is associated with a bifid straight sinus. CLINICAL PRESENTATION: A 35-year-old man presented with a headache and a lump on the back of the head. Physical examination revealed a firm, bony lesion approximately 4 x 4 cm in size. Lumbar puncture demonstrated an intraspinal pressure of 39 cm H2O. Neuroradiological studies revealed an epidermoid that compressed and almost completely occluded the torcula. INTERVENTION: After the tumor was resected, the intraspinal pressure decreased to 19 cm H2O and remained stable 6 months later. CONCLUSION: Pure venous obstruction causes increased intracranial pressure. Removal of the obstruction relieves the intracranial hypertension. In addition, computed tomographic venography is a safe and easy method of documenting torcular anatomy, and it was useful in the follow-up of this patient. Computed tomographic venography can demonstrate a double straight sinus, which is a congenital variant that may be associated with the epidermoid.

Ultrasound-guided hydrostatic reduction of childhood intussusception: technique and demonstration.

The authors review the technique of ultrasound-guided hydrostatic reduction of childhood intussusception and illustrate, in real-time fashion, the treatment of three cases with this technique. Two cases of successful reduction of ileocolic intussusception are demonstrated. The third case is an example of the complex fronded appearance of ileo-ileocolic intussusception and failed reduction. This technique is recommended as an alternative method for the treatment of childhood intussusception, as it does not involve ionizing radiation and is a simple and safe procedure.

A theory on the embryogenesis of oculo-auriculo-vertebral (Goldenhar) syndrome.

Oculo-auriculo-vertebral (OAV) syndrome is made up of anomalies, mainly of first and second branchial arch derivatives. Characteristic features include structural malformations of the external and middle ears, face, and jaw. It has been previously suggested that hemorrhage involving the first and second branchial arches causes hypoplasia and malformation of the face and auricle, but this theory cannot explain the multisystemic and protean manifestations of this disease. The theory set forth describes the cutaneous, facial, vertebral, and systemic anomalies in the OAV spectrum as a result of ectodermal nondisjunction early in development with subsequent mesodermal tethering. A subgroup of OAV may therefore be a disorder of ectodermal nondisjunction involving the otic placode similar to the spectrum of diseases such as occult spinal dysraphism that is associated with the same mechanism in the embryonic neuraxis. This would imply a molecular mechanism involving cell adhesion molecules that unify the two disease processes and explain the multisystem anomalies of the OAV syndrome.