Clinical and epidemiological features of patients with COVID-19 reinfection: a systematic review.

Recurrent positivity in a patient with COVID-19 may be due to various reasons, not necessarily reinfection. There is concern about the occurrence frequency of reinfection. Five databases and a preprint/preprint repository were searched. All case reports, case series, and observational studies were included. Bias was assessed for each study with the Newcastle-Ottawa Scale tool and reported according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA-2020). After eligibility, 77 studies were included for qualitative synthesis (52 case reports, 21 case series, and four case-controls; 1131 patients included). Of these, 16 studies described a second contact with the SARS-CoV-2 positive case, five studies described healthcare profession-related infection, ten studies described that the source of reinfection was likely to be from the community, one study described travel-related infection, nine studies described vulnerability-related infection due to comorbidity. The mean number of days from discharge or negative test to reinfection ranged from 23.3 to 57.6 days across the different included studies. The risk of bias for all case report/series studies was moderate/high. For observational studies, the risk of bias was low. Reinfection of patients with COVID-19 occurs between the first and second month after the first infection, but beyond, and 90 days have been proposed as a point to begin to consider it. The main factor for reinfection is contact with COVID-19 positive cases.

[Idiopathic short stature: definition and treatment]. / Talla baja idiopática: definición y tratamiento.

Short stature is the leading cause of consultation in Pediatric Endocrinology. Decreased growth velocity and abnormally short height are characteristic of several different nosologic entities. Some are well characterized, while others correspond to what is known as idiopathic short stature (ISS). ISS includes children who grow less than 2 SD of the mean height values corresponding to their peers of similar age and the same sex, in whom the known causes of short stature have been ruled out. The diagnosis of ISS does not include children who only present a constitutional delay in growth and development. Several clinical trials have demonstrated the efficacy of growth hormone (rhGH) treatment in achieving catch-up growth in these children. Therefore, ISS should be kept in mind in the diagnosis of patients with short stature and abnormal growth patterns, who may benefit from rhGH treatment.

Microbial sensor for new-generation cephalosporins based in a protein-engineered beta-lactamase.

A protein-engineered beta-lactamase, constructed by site-directed mutagenesis in Escherichia coli (E104M/G238S), and having broadened specificity, was able to degrade cephalosporins of first, second, and third generations. Manipulations of culture conditions allowed an increase in beta-lactamase specific activity by up to twofold. The resultant bacteria were used to construct an immersable whole-cell biosensor for the detection of new-generation cephalosporins. Cells were immobilized on agar membranes, which in turn were attached to the surface of a flat pH electrode, thus constituting a biosensor based on the detection of pH changes. The sensor was able to detect second- and third-generation cephalosporins: cefamandole (0.4-4 mM), cefotaxime (0.4-3.5 mM), and cefoperazone (0.3-1.85 mM). Response times were between 3.5 and 11 min, depending on the kind of cephalosporin tested. The biosensor was stable for at least 7 d, time during which up to 100 tests were performed.

[Hypoglycemia. First manifestation of diabetes mellitus in children (author's transl)]. / Hipoglucemia. Primera manifestación de diabetes "mellitus" en el niño

Nine children were sent to the authors for hypoglycemia and familial history of diabetes mellitus. After oral glucose load abnormal responses in insulin secretion were obtained in all of them, and in one patient blood glucose curve was consistent with probable chemical diabetes.

[Plasmatic levels of glucose and insulin in siblings of diabetic children (author's transl)]. / Valoración de glucosa e insulina plasmáticas en hermanos de diabéticos juveniles

Observation of glucose and plasmatic insulin curve after oral administration of glucose in 16 brothers of juvenile diabetics. The findings were: slight curve alterations that would be compatible with chemical diabetes.

[Effect of tolbutamide on plasmatic insulin and glucose in children treated with diphenylhydantoin (author's transl)]. / Respuesta de la insulina y glucosa plasmáticas a la tolbutamida, en niños tratados con difenilhidantoína

The response of the serum glucose and insulin to tolbutamide in six epileptic children before and after one month treatment with DH are studied. A significant increase of the glycemia after treatment with DH is observed having insulin values no statistically significant modification.

[HGH response to dihydroxyphenylalanine (L-dopa) (author's transl)]. / Respuesta de la hormona del crecimiento (HGH) a la dihidroxifenilalanina (L-dopa)

L-dopa, administered at dose levels of 250 mg., was used to assess HGH release in 36 children. In five cases of hypopituitary dwarfs no response was obtained and in the remaining 31 cases affected by short stature not of endocrine origin, the highest peak was produced 30' after the test (12.71 +/- 11.61 ng/ml; p less than 0.0005). Significant responses were also obtained at 60' (11.81 +/- 10.47 ng/ml; p less than 0.0005), 90' (7.25 +/- 7.49 ng/ml; p less than 0.0005) and 120' (4.8 +/- 4.86 ng/ml; p less than 0.005).

[Plasma levels of HGH, insulin and NEFA in diabetic children (author's transl)]. / Valoración plasmática de hormona de crecimiento (H.G.H.), insulina y ácidos grasos libres (N.E.F.A.) en niños diabéticos

Plasmatic levels of HGH, insulin and NEFA are measured after oral glucose loading in 14 diabetic children and are compared with those obtained in 7 normal children. The average values of HGH are higher in the diabetics at 0', 30', 60', and 190', and on the contrary the release of HGH which is produced at 90' and 120' with a glucose load is increased in the normal controls. None of these differences are significant. The insulin and NEFA response observed in the normal cases is not observed in the diabetics where the obtained values do not show variation with the administration of glucose.

[HGH release after I.M. glucagon injection]. / Respuesta de la hormona del crecimiento (HGH) al glucagón intramuscular

Intramuscular injection of glucagon was used to assess HGH release in 31 normal children and 4 hypopituitary dwarfs. The peak response in controls was obtained at 120 min. with values (nanograms) of 12.93 plus or minus 5.18 (p smaller than 0.0005). Values at 60 and 180 min. were equally significant when compared with basal (7.04 plus or minus 9.24, p smaller than 0.025 and 6.74 plus or minus 6.65, p smaller than 0.001). Hypopituitary dwarfs did not respond to glucagon injection.

[Hypoglycemic convulsions and hypopituitarism]. / Convulsiones hipoglucémicas. Primera manifestación de un hipopituitarismo

A case of hypopituitarism in a female, aged 6 months, whose first symptom consisted of hypoglycemic convulsions is reported. Making use of TRH we confirm the hypothalamic origin of pituitary failure. Substitution therapy controlled the episodes of convulsions and normalized the growth rate of the child.