Risk of transmission of SARS-CoV-2 on international flights, a retrospective cohort study using national surveillance data in England.

Background: It is not yet fully understood to what extent in-flight transmission contributed to the spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This study aimed to determine the occurrence and extent of SARS-CoV-2 transmission in-flight and assess factors associated with transmission risk to inform future control strategies.

Methods: Retrospective cohort study using data obtained from contact tracing of international flights arriving in England between 02/08/2021-15/10/2021.

Surge of lower respiratory tract group A streptococcal infections in England in winter 2022: epidemiology and clinical profile.

Background: Following low incidence of invasive group A streptococcal (iGAS) infections during the COVID-19 pandemic, marked increases were noted in many countries during 2022, particularly in children. In November 2022, severe presentations of lower respiratory tract infections (LRTIs), including empyema, were notified by clinicians across the UK. UKHSA investigated this rise with the aim of informing clinical management and public health response.

Epidemiology of Early Monkeypox Virus Transmission in Sexual Networks of Gay and Bisexual Men, England, 2022.

After community transmission of monkeypox virus was identified in Europe, interviews of 45 case-patients from England indicated transmission in international sexual networks of gay and bisexual men since April 2022. Interventions targeting sex-on-premises venues, geospatial dating applications, and sexual health services are likely to be critical for outbreak control.

A perivascular niche for multipotent progenitors in the fetal testis.

Androgens responsible for male sexual differentiation in utero are produced by Leydig cells in the fetal testicular interstitium. Leydig cells rarely proliferate and, hence, rely on constant differentiation of interstitial progenitors to increase their number during fetal development. The cellular origins of fetal Leydig progenitors and how they are maintained remain largely unknown.

Of Mice and Men: In Vivo and In Vitro Studies of Primordial Germ Cell Specification.

Specification of mouse primordial germ cells (PGCs), the precursors of sperm and eggs, involves three major molecular events: repression of the somatic program, reacquisition of pluripotency, and reprogramming to a unique epigenetic ground state. Gene knockout studies in mouse models, along with global transcriptome analyses, have revealed the key signaling pathways and transcription factors essential for PGC specification. Knowledge obtained from these studies has been utilized extensively to develop robust in vitro PGC induction models not only in mice but also in humans.

Origin and Differentiation of Androgen-Producing Cells in the Gonads.

Sexual reproduction is dependent on the activity of androgenic steroid hormones to promote gonadal development and gametogenesis. Leydig cells of the testis and theca cells of the ovary are critical cell types in the gonadal interstitium that carry out steroidogenesis and provide key androgens for reproductive organ function. In this chapter, we will discuss important aspects of interstitial androgenic cell development in the gonad, including: the potential cellular origins of interstitial steroidogenic cells and their progenitors; the molecular mechanisms involved in Leydig cell specification and differentiation (including Sertoli-cell-derived signaling pathways and Leydig-cell-related transcription factors and nuclear receptors); the interactions of Leydig cells with other cell types in the adult testis, such as Sertoli cells, germ cells, peritubular myoid cells, macrophages, and vascular endothelial cells; the process of steroidogenesis and its systemic regulation; and a brief discussion of the development of theca cells in the ovary relative to Leydig cells in the testis.

Methylation-dependent and independent regulatory regions in the Na,K-ATPase alpha4 (Atp1a4) gene may impact its testis-specific expression.

The α4 Na,K-ATPase is a sperm-specific protein essential for sperm motility and fertility yet little is known about the mechanisms that regulate its expression in germ cells. Here, the potential involvement of DNA methylation in regulating the expression of this sperm-specific protein is explored. A single, intragenic CpG island (Mα4-CGI) was identified in the gene encoding the mouse α4 Na,K-ATPase (Atp1a4), which displayed reduced methylation in mouse sperm (cells that contain α4) compared to mouse kidney (tissue that lacks α4 expression).

Necrotic bowel induces takotsubo-like myocardial injury.

Although chest pain in association with ST-segment electrocardiographic deviation is often indicative of cardiac ischemia, it has also been associated with noncardiac conditions. The case of a 63-year-old woman that we report here is extraordinary because her presentation of "acute abdomen" did not appear severe enough to warrant urgent surgical intervention, whereas the chest pain and electrocardiographic changes (supported by rising troponin levels) created strong clinical suspicion of acute coronary syndrome. Was the evidence of cardiac ischemia a primary event, or was it a sequela of an acute surgical condition? Noncardiac surgical cases associated with evidence of myocardial injury can be extremely challenging from a diagnostic and management perspective.

Non-atherosclerotic multiple coronary artery aneurysms.

A 52-year-old man underwent two-dimensional echocardiogram which showed moderate to severe aortic regurgitation (AR) and dilated ascending aorta. CT angiography (CTA) showed dilated ascending aorta (5 cm) and transoesophageal echocardiogram revealed bicuspid aortic valve. He underwent cardiac catheterisation which revealed triple vessel aneurysmal disease of the left anterior descending, left circumflex and right coronary artery.

Successful treatment of mobile right atrial thrombus and acute pulmonary embolism with intravenous tissue plasminogen activator.

An 89-year-old woman came with symptoms of progressively worsening dyspnoea at rest over the preceding week. She was normotensive, had elevated jugular venous pressure and clear lungs. ECG revealed atrial fibrillation with the rapid ventricular rate.

Imported cutaneous diphtheria, United Kingdom.

Cutaneous diphtheria is endemic in tropical countries but unusual in the United Kingdom. Four cases occurred in the United Kingdom within 2 months in 2002. Because cutaneous diphtheria causes outbreaks of both cutaneous and pharyngeal forms, early diagnosis is essential for implementing control measures; high diphtheria vaccination coverage must also be maintained.