Hypoparathyroidism is a rare endocrine disorder characterized by low calcium and high phosphate levels, in the setting of a low or inappropriately normal PTH level. Given its rarity, it has been classified as an orphan disease in the United States and by the European Commission. The first international conference on the management of hypoparathyroidism was convened in Florence Italy 2015 and resulted in the publication of detailed guidelines on the epidemiology, presentation, clinical features and management of hypoparathyroidism. Hypoparathyroidism may be associated with a spectrum of clinical manifestations, ranging from asymptomatic in the setting of mild hypocalcemia, to life threatening cardiac arrythmias, seizures or laryngospasm, in the setting of severe acute hypocalcemia. The most common cause is postsurgical hypoparathyroidism following anterior neck surgery, followed by autoimmune disorders and rarely genetic disorders. Establishing a diagnosis of hypoparathyroidism is important as it is associated with the development of kidney stones, renal insufficiency, cataracts, basal ganglia calcifications, as well as a reduced health-related quality of life. Most patients with chronic hypoparathyroidism require lifelong high dose calcium and activated vitamin D supplements. The goals of treatment are 3 fold, namely, relieve symptoms of hypocalcemia, raise calcium concentration to the low-normal range and avoid hypercalciuria. For those individuals who cannot maintain a stable serum and urine calcium with conventional calcium and activated Vitamin D regimens, the addition of recombinant PTH (1-84) is currently an option. The approval of recombinant PTH (1-84) represents a significant step forward in the management of this disorder.

Objective. To report a case of primary hyperparathyroidism in a pregnant patient, report the obstetric and neonatal outcomes, and review the relevant literature. Results. A 29-year-old primigravida was successfully treated for PHP with minimally invasive resection of a parathyroid adenoma in the second trimester of pregnancy. A healthy baby girl was delivered at 37-week gestation with an unremarkable neonatal course. To the best of our knowledge, this is the second case report in the literature utilizing intraoperative PTH during a parathyroidectomy in a pregnant woman. Conclusions. Primary hyperparathyroidism is a rare life-threatening condition that can present during pregnancy. The diagnosis can be difficult to establish during pregnancy, given the nonspecific symptoms related to hypercalcemia. However, a better understanding of the condition, improved diagnostic studies, and well-organized multidisciplinary management decisions can significantly reduce the morbidity and mortality associated with the disease during pregnancy. This case report is presented to highlight the value of early diagnosis and appropriate management of PHP during pregnancy.

In African American men serum, 25-hydroxyvitamin D (25-OHD) was below 30 ng/ml in 89% of subjects. In overall group, there was no correlation between 25-OHD and bone mineral density (BMD). A subgroup analysis of subjects with 25-OHD ≤15 ng/ml showed that serum 25-OHD was positively associated with BMD.

The measurement of serum 25-hydroxycalciferol (25-0H D) has proved to be a reliable index of the vitamin D nutritional status in man providing the renal 25-hydroxycalciferol-1 α-hydroxylase is functional. Since it is known that 25 OHD binds to α-globulins for its transport to the kidney, we have developed a competitive binding assay using an α-globulin enriched fraction (Cohn's fraction IV) as the ligand protein. A detection limit of 0.1 ng 25-OHD/tube was achieved and the non specific binding amounted to less than 3% of the initial binding. The intra- and inter-assay variations were 8.9 and 8.4% respectively. The reference values (nmol/1 ± 2 s.d.) obtained from samples of 40 children were 50.5 ± 21.5 with extremes of 34.8 and 95.2. The method thus proved to be a reliable and sensitive tool to assess serum 25-OHD levels.

Introduction: Osteoporosis remains under-diagnosed, particularly in African American men, despite the availability of reliable diagnostic tests. In women, several screening tools, including heel ultrasound and clinical assessment tools, reliably predict low bone mass, however the usefulness of these screening tools in African American men is unknown. The aim of this study was to determine the utility of screening tools, namely heel ultrasound, the osteoporosis self-assessment tool (OST), weight-based criterion (WBC) and body mass index (BMI), in screening for low bone mass in African American men. Materials and methods: African American men 35 years of age and older were invited to participate. The OST risk index is a score based on age and weight [(weight in kilograms - age in years) x 0.2]. Bone mineral density (BMD) of the heel was measured by heel ultrasound, and BMD of both the lumbar spine and hip were determined by dual energy X-ray absorptometry (DXA). One hundred and twenty-eight men fulfilled the inclusion criteria for our study. Results: The population prevalence of osteopenia and osteoporosis were 39% and 7%, respectively. Using a heel ultrasound T-score cut-off value of -1 or less, we predicted low bone mass (T-score of -2 or less at the hip) with a sensitivity of 83%, a specificity of 71% and an area under the curve (AUC) of 0.80. Using an OST cut-off value of 4, we predicted low bone mass with a sensitivity of 83%, a specificity of 57% and an AUC of 0.83. The OST risk index ranged from 18.1 to -6.1, based on which we categorized risk as: low, 5 or greater; moderate, 0-4; high, -1 or less. Of the men with a high-risk OST score, 87% had either osteopenia or osteoporosis based on World Health Organization (WHO) criteria. Using the WBC alone with a cut-off value of 85 kg, we predicted low bone mass with a sensitivity of 74%, a specificity of 50% and an AUC of 0.70. A BMI cut-off value of 30 or greater yielded a sensitivity of 83%, a specificity of 43% and an AUC of 0.70 for the diagnosis of low bone mass. Discussion: The prevalence of osteopenia and osteoporosis were unexpectedly high in outpatient African American male veterans, who are considered to be at low risk for low bone mass. Heel ultrasound was able to predict low bone mass with sufficiently high sensitivity and specificity for use as a screening tool. Surprisingly, WBC and BMI proved ineffective in predicting low bone mass with adequate sensitivity and specificity. The OST, a clinical formula based on weight and age, appeared to be an easy and reliable screening tool for identifying men at high risk for low bone mass.

We report the uncommon presentation of an unsuspected pheochromocytoma in a 76-year-old woman. Two years after surgery for acute aortic valve insufficiency and a diagnosis of diabetes, the patient presented with postural headaches, orthostatic dizziness, and palpitations. Physical examination confirmed intractable hypertension, orthostatic hypotension, and congestive heart failure secondary to progressive dilated cardiomyopathy. Based on her symptomatology, examination findings, and progressive dilated cardiomyopathy despite aortic valve replacement, a diagnosis of a pheochromocytoma was entertained. Twenty-four-hour urinary studies confirmed the presence of a catecholamine producing tumor. A magnetic resonance image revealed the presence of a 4.6-cm left adrenal mass, which characteristically enhanced on T2 imaging. After medical stabilization with phenoxybenzamine, she underwent a left robotic adrenalectomy. Histology confirmed a diagnosis of a pheochromocytoma. Two weeks later, she was normoglycemic and normotensive off all medications. The pheochromocytoma is a rare catecholamine-producing tumor, which can be lethal unless recognized and appropriately treated. A high degree of clinical suspicion is necessary, especially in the presence of confounding disease processes. A pheochromocytoma should be considered in the differential diagnosis of acute aortic valvular insufficiency in the setting of orthostatic hypotension, intractable hypertension, and newly diagnosed diabetes.

The objective of this study was to investigate whether low bone mass is directly associated with the severity of coronary atherosclerosis in men and postmenopausal women self-referred for evaluation of coronary atherosclerosis and osteoporosis. Low bone mass was evaluated by measurement of bone mineral density (BMD) using quantitative computerized tomography (QCT). Coronary atherosclerosis was evaluated by measurement of coronary calcium (CC) burden using electron beam computerized tomography (EBCT). Using a cross-sectional design, we tested the hypothesis that osteoporosis and coronary atherosclerosis are correlated, age-dependent processes. Study variables were BMD, CC scores, and other known risk factors for osteoporosis and atherosclerosis. Qualifying for the study were 313 postmenopausal women and 167 men. Men had higher baseline CC scores and higher body mass indexes compared to women. In females, those patients with coronary calcification were older and had significantly lower BMD compared to those without calcification. In males, those patients with coronary calcification were older. By univariate correlation analysis, the degree of coronary calcification was inversely associated with BMD in postmenopausal women (P < 0.0001) but not in men. However, after controlling for age, this association was absent for both men and postmenopausal women. Using multivariate logistic regression analysis in women and men separately, age was the only significant predictor of positive CC status and low BMD. Our study suggests that in postmenopausal women and in men, after controlling for age, osteoporosis and coronary atherosclerosis are independent processes.

We report an uncommon case of an intrasellar plasmacytoma presenting as a non-functional invasive pituitary macro-adenoma as the first manifestation of multiple myeloma.

Hypertension is the most common medical complication of pregnancy. Pheochromocytomas are a rare cause of hypertension in pregnancy, but potentially lethal for both the mother and fetus if not diagnosed early and treated appropriately. We report a case of a 35-year-old black woman who, at 32 weeks gestation, was found to have an adrenal mass on a routine antenatal ultrasound. She was subsequently found to have a right adrenal pheochromocytoma. This was managed medically with excellent maternal and fetal outcome. Complete resection of the tumor occurred immediately after a caesarian section delivery. Biochemical screening for a pheochromocytoma was negative 2 weeks after resection of the tumor. Pheochromocytoma is an endocrine and obstetric emergency. A pheochromocytoma should be considered in all patients with hypertension, especially if the hypertension is paroxysmal in nature. We propose the routine use of antenatal ultrasound to examine the adrenal glands in patients with hypertension. The use of plasma metanephrines and normetanephrines for the diagnosis and follow up of a pheochromocytoma in pregnancy are also discussed.

The binding site of monoclonal antibody Se155-4, which has been the object of successful crystallographic and antibody-engineering studies, is shown by solid-phase immunoassays to be complementary to a branched trisaccharide, alpha-D-Galp(1-->2) [alpha-D-Abep(1-->3)]-alpha-D-Manp(1, rather than to the tetrasaccharide repeating unit alpha-D-Galp(1-->2) [alpha-D-Abep(1-->3)]-alpha-D-Manp(1-->4) alpha-L-Rhap(1- of the bacterial antigen. Specificity for the 3,6-dideoxy-D-xylo-hexose (3,6-dideoxy-D-galactose) epitope present in Salmonella paratyphi B O-antigens was ensured by screening hybridoma experiments with glycoconjugates derived from synthetic oligosaccharides. Detailed epitope mapping of the molecular recognition by modified and monodeoxy oligosaccharide derivatives showed that complementary surfaces and three antibody-saccharide hydrogen bonds are essential for full binding activity. Both hydroxyl groups of the 3,6-dideoxy-D-galactose residue were obligatory for binding and consistent with the directional nature of their involvement in carbohydrate-protein hydrogen bonds; related tetrasaccharides built from the isomeric 3,6-dideoxyhexoses, 3,6-dideoxy-D-glucose, paratose, and 3,6-dideoxy-D-mannose, tyvelose were not bound by the antibody. Titration microcalorimetry measurements were consistent with the hydrogen-bonding map inferred from the crystal structure and suggest that the displacement of water molecules from the binding site accounts for the favorable entropy that accompanies binding of the native trisaccharide determinant. The protein sequences determined for the antibody VL and VH domains reveal somatic mutation of the VL germ line gene, implying that this antibody-binding site results from a mature antibody response.

The Fab a monoclonal anti-carbohydrate antibody, SYA/J6 (IgG3, κ, murine), raised against the O-polysaccharide antigen of the cell surface lipopolysaccharide of variant Y Shigella flexneri, a Gram negative bacterium, has been crystallized in the unliganded form and in complex with tri- and pentasaccharide antigens. The three crystal forms belong to the tetragonal space group P43212, or P 41212, with very similar unit cell dimensions and an asymmetric unit that contains one molecule of about 50,000 Daltons, and a fourth crystal form belongs to monoclinic space group P21, that contains four molecules of Fab in an asymmetric unit. Whereas diffractions of these crystals on an area detector-rotating anode system extend to only about 3·5 Å resolution, those measured using an imaging plate and synchrotron radiation at the Photon Factory facility extend to 2·5 Å

The carbohydrate-binding site in Fab fragments of an antibody specific for Salmonella serogroup B O-polysaccharide has been probed by site-directed mutagenesis using an Escherichia coli expression system. Of the six hypervariable loops, the CDR3 of the heavy chain was selected for exhaustive study because of its significant contribution to binding-site topography. A total of 90 mutants were produced and screened by an affinity electrophoresis/Western blotting method. Those of particular interest were further characterized by enzyme immunoassay, and on this basis seven of the mutant Fabs were selected for thermodynamic characterization by titration microcalorimetry. With regard to residues that hydrogen bond to ligand through backbone interactions, Gly102H could not be substituted, while several side chains could be introduced at Gly100H and Tyr103H with relatively little effect on antigen binding. There was, however, a preference for nonpolar side chains at position 103H. Substitution of His101H with carboxylate and amide side chains gave mutants with binding affinities approaching that of the wild type; complete side-chain removal by mutation to Gly was tolerated with a 10-fold reduction in binding constant. Analysis of binding by titration microcalorimetry revealed some dramatic thermodynamic changes hidden by the similarity of the binding constants. Similar effects were observed with residue changes in an Arg-Asp salt-bridge at the base of the loop. These results indicate that alterations to higher affinity anti-carbohydrate antibodies are characterized by an enthalpy-entropy compensation factor which allows for fundamental changes in the nature of the binding interactions but impedes engineering for increases in affinity.

The Fab from an IgG1, lambda murine monoclonal antibody with specificity for the O-polysaccharide antigen of Salmonella typhimurium has been crystallized in the absence and presence of hapten. The conditions for crystal growth were vapor diffusion equilibration with 16 to 23% polyethylene glycol 8000 solutions. Data have been collected from crystals of the complex in space group P212121, a = 60.6 A, b = 111.3 A, c = 61.1 A, and refinement of a molecular replacement solution is underway.

A 658 bp DNA sequence corresponding to the murine lambda 1 chain of a monoclonal antibody, Se155-4, specific for the Salmonella serotype B O-antigen, was designed using Escherichia coli preferred codons and chemically synthesized by ligation of synthetic fragments into a linearized plasmid followed by transformation into E. coli. A synthetic signal peptide (ompA) was fused to express the L chain as a free polypeptide into the periplasm of E. coli cells. After isolation and purification, heterologous recombination of the E. coli L chain with mouse H chain gave an active antigen-binding protein. The activity was 15-20% when compared to protein created by an equivalent association of isolated natural mouse L and H chains as measured by a direct EIA assay. In inhibition experiments with the polysaccharide antigen, the two proteins showed identical titration curves and 50% inhibition points, indicating comparable KA values.