Unilateral Graves’ Orbitopathy in a patient with Marine-Lenhart Syndrome: A case report

Thyroid eye disease (TED) is the most common symptoms of Graves’ disease. This condition commonly manifests bilaterally and symmetrically. The most prominent symptoms are lid retraction, exophthalmos, and diplopia. Rarely, individuals with Graves’ disease may show asymmetrical or unilateral eye symptoms. Marine-Lenhart syndrome is a variant of Graves’ disease with occasional hyperactive nodules. We introduce a 36-year-old Omani male patient who presented to the endocrinology outpatient department of Sultan Qaboos University Hospital, Muscat, Oman, in 2022 with unilateral eye proptosis and was subsequently found to have Graves’ disease. This case presents a rare Graves’ disease variant with unilateral goiter and orbitopathy. Keywords: Graves’ disease; Unilateral proptosis; Thyroid Eye Disease; Graves ’orbitopathy; Marine-Lenhart syndrome

Electronically-Controllable Floating Inductor using OMA with Enhanced Input Dynamic Range

Abstract Recently a new formulation for realizing a floating inductance (FI) using an OMA, which takes into account the dominant pole of the op-amp employed in the OMA, without requiring any external capacitor was proposed. The proposition, however, suffered from a limited inputdynamic-range of operation owing to limited open-loop signal handling capability of the op-amp used. In this paper we propose an improved FI formulation with increased input signal handling capability. The electronically controllable floating inductance feature of the resulting circuit has been shown by replacing all the building blocks of the FI formulation by their CMOS counterparts. The workability of the proposed FI has been demonstrated by PSPICE simulations

A novel mutation in HSD11B2 causes apparent mineralocorticoid excess in an Omani kindred

Apparent mineralocorticoid excess (AME) is a rare autosomal recessive genetic disorder causing severe hypertension in childhood due to a deficiency of 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), which is encoded by HSD11B2. Without treatment, chronic hypertension leads to early development of end-organ damage. Approximately 40 causative mutations in HSD11B2 have been identified in ∼100 AME patients worldwide. We have studied the clinical presentation, biochemical parameters, and molecular genetics in six patients from a consanguineous Omani family with AME. DNA sequence analysis of affected members of this family revealed homozygous c.799A>G mutations within exon 4 of HSD11B2, corresponding to a p.T267A mutation of 11βHSD2. The structural change and predicted consequences owing to the p.T267A mutation have been modeled in silico. We conclude that this novel mutation is responsible for AME in this family

Clinical, genetic, and structural basis of apparent mineralocorticoid excess due to 11β-hydroxysteroid dehydrogenase type 2 deficiency

Mutations in 11β-hydroxysteroid dehydrogenase type 2 gene (HSD11B2) cause an extraordinarily rare autosomal recessive disorder, apparent mineralocorticoid excess (AME). AME is a form of low renin hypertension that is potentially fatal if untreated. Mutations in the HSD11B2 gene result either in severe AME or a milder phenotype (type 2 AME). To date, ∼40 causative mutations have been identified. As part of the International Consortium for Rare Steroid Disorders, we have diagnosed and followed the largest single worldwide cohort of 36 AME patients. Here, we present the genotype and clinical phenotype of these patients, prominently from consanguineous marriages in the Middle East, who display profound hypertension and hypokalemic alkalosis. To correlate mutations with phenotypic severity, we constructed a computational model of the HSD11B2 protein. Having used a similar strategy for the in silico evaluation of 150 mutations of CYP21A2, the disease-causing gene in congenital adrenal hyperplasia, we now provide a full structural explanation for the clinical severity of AME resulting from each known HSD11B2 missense mutation. We find that mutations that allow the formation of an inactive dimer, alter substrate/coenzyme binding, or impair structural stability of HSD11B2 yield severe AME. In contrast, mutations that cause an indirect disruption of substrate binding or mildly alter intramolecular interactions result in type 2 AME. A simple in silico evaluation of novel missense mutations could help predict the often-diverse phenotypes of an extremely rare monogenic disorder

Current-Mode Universal Biquad Using Current Followers: A Minimal Realization

A new universal biquad filter is presented which employs a minimum number of active elements (only three current followers (CF)) along with a minimum number of passive components (i.e. only two resistors and two capacitors). The new circuit provides all the five standard filter responses (namely lowpass, bandpass, highpass, notch and allpass) from the same structure without requiring any component matching conditions and with explicit current outputs available from high output impedance terminals. The workability of the proposed universal biquad, realised with unity-gain current followers implemented in 0.35 µm CMOS and operated from 1.65 volts DC power supplies, is established by SPICE simulations