Systematic review of incidence, risk factors, prevention and treatment of post-laryngectomy hypoparathyroidism

Purpose Post-laryngectomy hypoparathyroidism is associated with significant short- and long-term morbidities. This systematic review aimed to determine incidence, risk factors, prevention and treatment of post-laryngectomy hypoparathyroidism. Methods Medline, EMBASE and the Cochrane library were searched for relevant articles on hypocalcaemia and/or hypoparathyroidism after laryngectomy or pharyngectomy. Two authors independently screened titles and abstracts from the search. Data from individual studies were collated and presented (without meta-analysis). Quality assessment of included studies was undertaken. The review protocol was registered in the PROSPERO database (CRD42019133879). Results Twenty-three observational studies were included. The rates of transient and long-term hypoparathyroidism following laryngectomy with concomitant hemi- or total thyroidectomy ranged from 5.6 to 57.1% (n = 13 studies) and 0 to 12.8% (n = 5 studies), respectively. Higher transient (62.1–100%) and long-term (12.5–91.6%) rates were reported in patients who had concomitant oesophagectomy and total thyroidectomy (n = 4 studies). Other risk factors included bilateral selective lateral neck dissection, salvage laryngectomy and total pharyngectomy. There is a lack of data on prevention and management. Conclusion Hypoparathyroidism occurs in a significant number of patients after laryngectomy. Patients who underwent laryngectomy with concomitant hemithyroidectomy may still develop hypoparathyroidism. Research on prevention and treatment is lacking and needs to be encouraged

The leading particle effect from light quark fragmentation in charm hadroproduction

The asymmetry of $D^-$ and $D^+$ meson production in $\pi^-N$ scattering observed by the E791 experiment is a typical phenomenon known as the leading particle effect in charm hadroproducton. We show that the phenomenon can be explained by the effect of light quark fragmentation into charmed hadrons (LQF). Meanwhile, the size of the LQF effect is estimated from data of the E791 experiment. A comparison is made with the estimate of the LQF effect from prompt like-sign dimuon rate in neutrino experiments. The influence of the LQF effect on the measurement of nucleon strange distribution asymmetry from charged current charm production processes is briefly discussed.Comment: 6 latex pages, 1 figure, to appear in EPJ

Primary hyperparathyroidism in children, adolescents, and young adults

Primary hyperparathyroidism (HPT) is considered a rare disease in children and an uncommon one in adolescents and young adults. Until 1975, only 60 children under the age of 16 years had been reported with proven HPT. Most had symptoms of weakness, irritability, anorexia, and weight loss. Severe hypercalcemia (serum calcium>15 mg/ 100 ml) and radiologic evidence of bone changes were common findings, and suggested delayed diagnoses . This report is based on the clinical and laboratory findings in 53 young patients with proven primary HPT (range: 1–30 years of age) from 1971 to 1980, treated in one hospital. There were 29 male and 24 female patients, 26 of whom developed symptoms before age 18. Common symptoms included hematuria and renal colic (50%), renal calculi (50%), and hypertension with (6%) and without (3%) severe headaches. Although 64.2% of patients had adenomas, only 54% of patients under 18, and as many as 77.8% over 18, had them. The incidence of hyperplasia was markedly increased in the patients under 18 (38%) as compared to the patients over 18 (18.5%) or the group taken as a whole (30.2%). The following associated diseases were identified: MEA I syndrome (4); MEA II syndrome (4); von Recklinghausen's neurofibromatosis; papillary carcinoma of thyroid; craniopharyngioma; and multiple metaphyseal chondromatosis. One child had hereditary neonatal parathyroid hyperplasia . Primary hyperparathyroidism is more common than previously suspected in young people. Symptoms of renal stones, hypertension, persistent headaches, unexplained anorexia, and weight loss should prompt evaluation for primary HPT. If hyperplasia is found, the patient and family should be investigated for associated endocrinopathies . L'hyperparathyroïdie est considérée une maladie extraordinaire des infants et bien rare des adolescents et des jeunes adultes. Jusqu'à 1975, seulement 60 enfants qui avaient moins de 16 ans étaient rapportés avec l'hyperparathyroïdie verifiée. La majorité avaient les symptômes de faiblesse, irritabilité, anorexie et perdu des poids. L'hypercalcémie severe (calcémies > 15 mg/100 ml) et l'évidence radiologique d'abnormalitiés osseux sont les conclusions ordinaires, et cela donne l'idée que le diagnostic était tard.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41310/1/268_2005_Article_BF01655371.pd

Genetic insights into biological mechanisms governing human ovarian ageing

Reproductive longevity is essential for fertility and influences healthy ageing in women, but insights into its underlying biological mechanisms and treatments to preserve it are limited. Here we identify 290 genetic determinants of ovarian ageing, assessed using normal variation in age at natural menopause in approximately 200,000 women of European ancestry. These common alleles were associated with clinical extremes of age at natural menopause; women in the top 1% of genetic susceptibility have an equivalent risk of premature ovarian insufficiency to those carrying monogenic FMR1 premutations. The identified loci implicate a broad range of DNA damage response (DDR) processes and include loss-of-function variants in key DDR-associated genes. Integration with experimental models demonstrates that these DDR processes act across the lifecourse to shape the ovarian reserve and its rate of depletion. Furthermore, we demonstrate that experimental manipulation of DDR pathways highlighted by human genetics increases fertility and extends reproductive life in mice. Causal inference analyses using the identified genetic variants indicate that extending reproductive life in women improves bone health and reduces risk of type 2 diabetes, but increases the risk of hormone-sensitive cancers. These findings provide insight into the mechanisms that govern ovarian ageing, when they act, and how they might be targeted by therapeutic approaches to extend fertility and prevent disease