Nonparametric Testing of Body Mass Index as a Predictor of Severe Noma: Assessing Potential Association.

Noma, a devastating facial disease, primarily affects impoverished populations in low- and middle-income countries, often leading to severe disfigurement or fatality if untreated. Studies suggest malnutrition is a significant risk factor for noma, yet the association between body mass index (BMI) in kilograms per square meter and tissue damage severity remains underexplored. This study aimed to investigate the relationship between BMI and tissue damage severity among noma cases in Ethiopia. A retrospective analysis of medical records from Facing Africa's database covering noma cases treated between 2007 and 2019 was conducted. A standardized data collection template recorded demographic and clinical data, including patient demographics, BMI, and tissue damage severity levels. JASP statistical software was used for analysis. Analysis of 228 noma cases revealed a mean BMI of 17.8 kg/m2, ranging from 11.5 to 28.3 kg/m2. Females exhibited a higher mean BMI (18.3 kg/m2) than males (16.9 kg/m2). Differences in BMI distributions between major (67) and minor (30) tissue damage categories were observed, with "minor" cases having a slightly higher mean BMI. The study found a statistically significant association between BMI and tissue damage severity (P = 0.03), indicating that tissue damage due to noma worsened as BMI decreased. Nonparametric tests confirmed this association's significance. This study highlights low BMI as a predictor of severe noma. Public health interventions should focus on malnutrition to reduce noma severity and psychosocial and functional morbidity and improve outcomes. However, additional factors influencing the progression of noma and the severity of associated tissue damage require further investigation.

Surgical Procedures, Complications, and Durations in Patients with Noma Disease: A Cross-sectional Study.

Background: Noma is a devastating disease that causes severe destruction of facial tissue, necessitating comprehensive surgical intervention for functional restoration and improved quality of life. This cross-sectional study aimed to identify common surgical procedures used for noma defect reconstruction in Ethiopia, analyze their durations, and assess associated complications. Methods: The study retrospectively analyzed noma patient records from Facing Africa's database, covering electronic medical data from 2007 to 2019, and utilized SPSS version 2020 for analysis. Results: Facing Africa treated 235 noma cases (2007-2019) with 438 procedures. The most commonly used surgical technique was reconstructive surgery, which encompassed two or more other surgical methods and was used in 177 cases. This was followed by the submental flap in 47 cases and ankylosis release in 35 cases. The study also found complications in 11 cases, including flap necrosis, abscesses, and ankylosis-related mouth restriction. Additionally, the analysis of 102 noma cases revealed significant variations in the duration of surgical procedures, ranging from 10 to 48 hours for specific cases, with the majority (63.7%) requiring 2 to 5 hours. The mean duration of noma surgery was calculated to be 4.08 hours. Conclusions: Comprehending common surgical techniques, complications, and durations benefits surgical planning, resource allocation, and patient care. Thus, the results of this study are a useful contribution to the development of effective noma treatment. However, further research and continuous efforts are needed to refine surgical practices, address potential complications, and enhance patient care in the battle against this devastating disease.

Anaerobic dechlorination and redox activities after full-scale Electrical Resistance Heating (ERH) of a TCE-contaminated aquifer.

The effects of Electrical Resistance Heating (ERH) on dechlorination of TCE and redox conditions were investigated in this study. Aquifer and groundwater samples were collected prior to and after ERH treatment, where sediments were heated to approximately 100 degrees C. Sediment samples were collected from three locations and examined in microcosms for 250 to 400 days of incubation. Redox activities, in terms of consumed electron acceptors, were low in unamended microcosms with field-heated sediments, although they increased upon lactate-amendment. TCE was not dechlorinated or stalled at cDCE with field-heated sediments, which was similar or lower compared to the degree of dechlorination in unheated microcosms. However, in microcosms which were bioaugmented with a mixed anaerobic dechlorinating culture (KB-1) and lactate, dechlorination past cDCE to ethene was observed in field-heated sediments. Dechlorination and redox activities in microcosms with field-heated sediments were furthermore compared with controlled laboratory-heated microcosms, which were heated to 100 degrees C for 10 days and then slowly cooled to 10 degrees C. In laboratory-heated microcosms, TCE was not dechlorinated and redox activities remained low in unamended and lactate-amended sediments, although organic carbon was released to the aqueous phase. In contrast, in field-heated sediments, high aqueous concentrations of organic carbon were not observed in unamended microcosms, and TCE was dechlorinated to cDCE upon lactate amendment. This suggests that dechlorinating microorganisms survived the ERH or that groundwater flow through field-heated sediments carried microorganisms into the treated area and transported dissolved organic carbon downstream.

Hypothalamic tumor presenting as anorexia nervosa.

The authors describe a patient with symptoms of anorexia nervosa who was initially treated on a psychiatric ward but was later found to have a hypothalamic tumor. They recommend repeated neurological and endocrine evaluations for patients with anorexia nervosa who are unresponsive or only partially responsive to psychiatric treatment. Initially negative medical evaluations, obvious psychopathology, and even some response to treatment may all prove insufficient to rule out organic disease.

Accommodation responses and ageing.

PURPOSE: To study the impact of age on accommodation dynamics. METHODS: Monocular accommodation responses were measured continuously using a modified Canon Auto Ref R1 infrared optometer. The stimulus was a single letter oscillating sinusoidally between 2.38 and 1.33 D providing a stimulus amplitude of 0.52 D, about a mean level of 1.86 D. Response characteristics were used to quantify gain and phase. Step responses were also recorded between these stimulus vergence levels for calibration purposes and to measure reaction and response times. Nineteen visually normal subjects 18 to 49 years of age participated, and 11 frequencies were used in the range 0.05 to 1.0 Hz. A key feature of the experimental design was to use a stimulus vergence range that lay within the amplitude of accommodation of all the observers. RESULTS: Accommodation gain reduced and phase lag increased with age, particularly at the higher frequencies used. No strongly significant change with age was found for reaction and response times or accommodation velocity, and results were similar for both far-to-near and near-to-far responses. Response amplitude for the step change in target vergence declined with age, and substantial differences were found between the measured and predicted (from reaction time) phase lags at 1.0 Hz as a function of age. Young observers showed a phase lag that was shorter than predicted, whereas older observers' measured phase lags were considerably larger than predicted. CONCLUSIONS: Results show that for a target oscillating sinusoidally in a predictable manner at a modest amplitude, the main ageing effects occur in phase lag, which is appreciably longer than predicted from reaction times in the older observers. The effects of ageing on gain were not as marked. Although responses to small step changes do reduce with age, there is no evidence of increased response times with ageing. In general, accommodation function in the middle-aged eye is quite robust despite a dwindling amplitude of accommodation. These results provide evidence of accommodative vigor in youth and a slowing of accommodation with ageing.

Central visual fields for short wavelength sensitive pathways in glaucoma and ocular hypertension.

While conventional clinical visual acuity and kinetic visual fields may be essentially normal in ocular hypertension and early stages of glaucoma, other foveal aspects of vision (eg color, spatial and temporal contrast sensitivity) may be quite abnormal. Specifically, a selective vulnerability of the short wavelength sensitive (SWS) visual pathways in these conditions has previously been noted. Here we studied the central visual fields of 33 primary open angle glaucoma (POAG) patients, 32 ocular hypertensives (OHT), and 24 age-matched normal controls using blue and yellow test flashes on bright yellow backgrounds. SWS cone and MWS and/or LWS cone pathway sensitivities were measured at the fovea and at 2.5 degrees, 5 degrees, 10 degrees and 15 degrees eccentricities, in either the inferior temporal (for OHT) or horizontal nasal retina (for POAG). As expected, all groups had normal sensitivity to yellow flashes--detected by LWS and/or MWS cones--in these meridians. By comparison, for the blue flashes--detected by the SWS cones--the POAG and OHT groups had sensitivity deficits, uniformly across the central visual field, of about 6X and 1.8X, respectively, compared to normals. While six of 31 (19%) OHT subjects had localized glaucomatous field defects (greater than 0.4 log units) in the non-foveal inferior temporal retina, none of the 12 OHT subjects who were also tested in the horizontal nasal retina showed loss in this meridian. Finally, while no POAG subjects had localized sensitivity loss for yellow flashes in the horizontal nasal retina, four did show local field defects with blue test flashes.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical measures of central vision function in glaucoma and ocular hypertension.

A generalized loss of visual sensitivity, even for foveal targets, has been reported as an early sign of glaucoma. In the present study of central vision, we used relatively simple and rapid clinical tests of color thresholds, color discrimination, and spatial contrast sensitivity to compare the vision of three age-matched groups of patients who had primary open angle glaucoma (n = 33) or ocular hypertension (n = 32) as well as normal subjects (n = 24). The largest sensitivity losses for both glaucoma and ocular hypertensive groups were disclosed by a color threshold test with blue lights designed to isolate the blue-sensitive pathways of the visual system. The loss of sensitivity for both the glaucoma group and the ocular hypertensive group is consistent with recent reports (from postmortem studies of human eyes) of extensive axon death even in the absence of glaucomatous field defects.

The simultaneous interocular brightness sense test. A test of optic nerve function.

OBJECTIVE: To describe and establish control data from controls for a simultaneous interocular brightness sense test in which the apparent brightness of two independently viewed light patches was compared. DESIGN: Dichoptic viewing was achieved by dissociation of right and left eyes using a septum and cross-polarization. Brightness matches were obtained by using adjustments to the illumination of the left retina while the illumination of the right retina was kept constant. OBSERVERS: Ninety-one control observers (age range, 20 to 91 years) participated in the study to provide normal brightness-matching data. RESULTS: Effects from ocular dominance, age, and long- and short-term adaptation were negligible, but the test was sensitive to anisocoria. Just noticeable differences in dichoptic brightness matching were proportional to retinal illuminance; this finding was consistent with the Weber-Fechner law. CONCLUSION: The test is quick and simple to complete and appears to offer considerable scope for the assessment of visual function when differences in the functional integrity of the optic nerves of the right and left eyes are suspected.

Simultaneous interocular brightness sense testing in ocular hypertension and glaucoma.

OBJECTIVE: To investigate the performance of the simultaneous interocular brightness sense test in patients with ocular hypertension and primary open angle glaucoma (POAG). DESIGN: Brightness matches were obtained for an age-matched control sample and for patients with ocular hypertension and POAG. In addition, for the patients with POAG, visual field defects were quantified and a risk factor count was established for those with ocular hypertension. PATIENTS: Nineteen patients with ocular hypertension, 20 patients with POAG, and 61 age-matched controls participated in the study. RESULTS: Seven patients with ocular hypertension exhibited brightness perception asymmetry outside normal limits for age-matched controls. Of these, six were at high risk of having glaucoma develop and only one of the remaining 12 was found to be at similar risk. All 20 patients with established POAG had results outside the normal limits for a test sensitivity of 100%. Three control observers had abnormal results, giving a test specificity of 95%. CONCLUSION: The simultaneous interocular brightness sense test is quick and simple to perform and is suitable for a wide age range of patients. It warrants further assessment as a means of screening for ocular hypertension and glaucoma.

On the linearity of accommodation dynamics.

Available experimental data on the gain and phase lags in the closed-loop accommodation responses to stimuli whose dioptric vergence changes sinusoidally with time are examined. It is shown that both phase lags and gain change almost linearly with the temporal frequency of the stimulus. This implies that the phase lags correspond to a frequency-independent time delay and that, if the system is linear, the impulse response should take a symmetrical (sin x/x)(2) form, with a corresponding standard form of step response. Comparison of this derived step response with the quasi-exponential results found experimentally underlines the limitations of attempting to generalize dynamic accommodation performance from responses obtained with predictable sinusoidally-changing stimuli and the application of a linear model. Consideration of the frequency response which would lead to an exponential step response supports the argument that, although the gain results obtained with sinusoidal stimuli are reasonably representative of those applying with other forms of stimulus, the predictable nature of sinusoidally-changing stimuli makes the derived phase lags inapplicable to non-predictable step or other stimuli. Other limitations in linear models of the response are discussed.

Accommodation as a function of age and the linearity of the response dynamics.

The changes with age in the accommodation responses to dynamic stimuli can reveal useful information on the factors underlying presbyopia development. Analysis of the monocular accommodation responses of 19 normal observers (ages 18-49 years) to stimuli whose vergence varied sinusoidally with time at different temporal frequencies (peak-to-peak stimulus 1.33-2.38 D, at 0.05-1.00 Hz) showed that at all ages both the gain and phase of the response were essentially linear functions of the temporal frequency. Extrapolation of least-squares, regression line fits to the gain data for each subject gave the gain at zero frequency, G0, and the cut-off frequency, fc, at which the gain fell to zero. G0 reduced with age but fc remained essentially constant at about 1.7 Hz, up to at least the age of about 40. The magnitude of the response to step stimuli covering the same stimulus range was well correlated with the value of G0. The linear changes in phase lag with temporal frequency corresponded to simple time delays td. The time lag varied from close to zero for the youngest subjects to about 0.5 s for the subjects in their late forties. There was substantial variation between the responses of subjects of similar age: those subjects with high values of G0 also tended to have low values of td, both effects probably being due to the superior ability of some individuals to predict the sinusoidal changes in the accommodation stimulus. Comparison of theoretical step responses, derived by applying linear theory to the parameters obtained from the results for the sinusoidal stimuli, with the actual responses to unpredictable steps for the same subjects supports the view that prediction effects and other possible factors make linear theory inapplicable to this type of data. The results are discussed in the context of current ideas on the development of presbyopia: it is suggested that the constancy of fc with age is the result of the ciliary body maintaining its efficiency, whereas the fall in G0 and increase in td result from increases in lens rigidity.

The Pulfrich phenomenon and its alleviation with a neutral density filter.

A case is described in which a presumed vascular accident resulted in long-standing visual difficulties in both reading and the analysis of vectors of moving objects. Clinical examination revealed minimal right optic atrophy with a relative superior altitudinal visual field defect associated with a positive Pulfrich effect. A partial head turn to the right in association with paresis of saccades and pursuit eye movements to the right was also evident. Spectacles for distance which incorporated a neutral density filter before the left eye were prescribed. These practically eliminated the Pulfrich effect and alleviated the problems of vector analysis. A near correction was provided which incorporated prisms with bases to the right. This eliminated the reading difficulties. The visual problems experienced by patients suffering from a positive Pulfrich effect are described and discussed.

Dynamics of the accommodation response to abrupt changes in target vergence as a function of age.

The dynamic accommodation responses to small, abrupt changes in an accommodation stimulus were studied in two experiments. In the first, responses of 19 subjects with ages distributed between 18 and 49 years were measured for step stimuli of +/- 1.05 D. In the second, responses to small step stimuli (+/- 0.75, +/- 1.75 D) were recorded for a group of six 'young' (mean age 22, range 16-26 years) and six 'old' (mean age 42, range 36-48 years) subjects. In both experiments, the low target vergences always lay within the accommodation range of all subjects. Whether the data were analysed in terms of simple reaction and response times, or in terms of the frequency response, no marked systematic changes with age were found in the dynamics of the response in either of the experiments. It is concluded that, for small stimuli within the amplitude of accommodation, the response dynamics over the adult age range studied remain remarkably constant, even though the amplitude progressively reduces with age as complete presbyopia is approached.

[Predictive value of the reactive hyperemia test as an indicator for lumbar sympathectomy]. / Valeur prédictive du test d'hyperémie réactionnelle dans l'indication de sympathectomie lombaire.

Seventy-five patients had a lumbar sympathectomy for chronic arteritis of the lower limbs. This study was done to assess the predictive value of Hillestad's test (potential of vasodilatation) and that of the deep breath test (sympathic stimulation), realised by digital strain gauge plethysmography. Were considered a success the patients with claudication who doubled their walking distance and those with rest pain or gangrene who suffered no more or healed. Globally speaking, 49% were a success. A positive response to Hillestad's test was followed by an 83% overall success rate. For claudicants with femoropopliteal lesions the predictive success rate was 95% with a positive Hillestad's test, against 60% globally; for patients with rest pain or gangrene or with distal lesions the success probability was around 60% if Hillestad's test was positive. A negative response to Hillestad's test was always followed by a failure in diabetics. A better predictability ought to be obtained with the adjunction of a deep breath test.

[The use of labelled albumin microspheres in the study of arteriovenous shunting in varicosities of the lower limbs (author's transl)]. / Utilisation de microsphères d'albumine marquées dans l'étude du shuntage artério-veineux des varices des membres inférieurs.

The greater proportion of oxygen in the blood circulating in veins of the lower limbs bought to attention the possibility of pre-capillary arteriovenous shunting. The intra-arteriel injection of Technetium labelled serum albumin microspheres enables one to quantify arteriovenous shunts greater than 25 microns. The authors made a comparative study of arterio-venous shunting by blood gases analysis and isotopic techniques in twenty patients. The results seem to deny the existence of arteriovenous shunts in the genesis of essential varicose veins in the lower limb.

Impaired perception of moving objects after minor injuries to the eye and midface: the Pulfrich phenomenon.

Delayed conduction along one optic nerve can result in an incorrect appreciation of moving objects. The temporal mismatch between the two different pathways results in altered perception of the vector of a moving target and is known as 'the Pulfrich phenomenon'. This is a well-recognised handicap in patients with multiple sclerosis, but has not previously been reported as a consequence of injury. All 187 patients who presented during 1991 with reduced visual acuity as a result of midfacial injuries were examined with a pendulum. Six had the defect and five of these had symptoms. In each case the patients were disturbed by car travel, because they perceived oncoming traffic moving in a hyperbolic curve towards them. These patients have been examined in detail and given a tinted lens for the normal eye to eliminate the illusion by delaying the input from the normal side to equal that on the damaged side. We recommend that this phenomenon is sought in all patients with mid-facial injuries or with later evidence of mild traumatic optic neuropathy, particularly if they are disturbed by car travel.