RESUMEN
Nontuberculous mycobacteria (NTM) commonly manifest as cervical lymphadenitis in immunocompetent children. Only a few species, such as Mycobacterium avium complex (MAC), cause infection in children. With recent advances in gene sequencing, Mycobacterium interjectum has been identified as a rare cause of adenitis in children, with at least ten cases reported since 1993. Curative treatment for NTM lymphadenitis, particularly when caused by MAC, usually involves complete surgical excision of the affected lymph nodes. This case report highlights successful treatment of submandibular lymphadenitis caused by M. interjectum in a paediatric patient, despite multi-drug resistance in vitro.
RESUMEN
Cat scratch disease (CSD) typically presents as regional lymphadenopathy, following inoculation via scratch, bite, or lick to an open wound by a young cat. Annual prevalence is 22,000 cases in the United States. Although CSD is self-limiting in the majority of cases, CSD can manifest in varying presentations and affect multiple organ systems. Serology testing for Bartonella henselae antibodies is a practical diagnostic tool but has limitations. Therefore, it is important for medical providers to recognize CSD in its multiple forms, as antibacterials are indicated in certain presentations. The following cases focus on cardiac and ophthalmic manifestations, as well as delayed seroconversion.
RESUMEN
Researchers have shown that adult zebrafish have the potential to regenerate 20% of the ventricular muscle within two months of apex resection, and neonatal mice have the capacity to regenerate their heart after apex resection up until day 7 after birth. The goal of this study was to determine if large mammals (porcine heart model) have the capability to fully regenerate a resected portion of the left ventricular apex during the neonatal stage, and if so, how long the regenerative potential persists. A total of 36 piglets were divided into the following groups: 0-day control and surgical groups and seven-day control and surgical groups. For the apex removal groups, each piglet was subjected to a partial wall thickness resection (~30% of the ventricular wall thickness). Heart muscle function was assessed via transthoracic echocardiograms; the seven-day surgery group experienced a decrease in ejection fraction and fractional shortening. Upon gross necropsy, for piglets euthanized four weeks post-surgery, all 0-day-old hearts showed no signs of scarring or any indication of the induced injury. Histological analysis confirmed that piglets in the 0-day surgery group exhibited various degrees of regeneration, with half of the piglets showing full regeneration and the other half showing partial regeneration. However, each piglet in the seven-day surgery group demonstrated epicardial fibrosis along with moderate to severe dissecting interstitial fibrosis, which was accompanied by an abundant collagenous extracellular matrix as the result of a scar formation in the resection site. Histology of one 0-day apex resection piglet (briefly lain on and accidentally killed by the mother sow three days post-surgery) revealed dense, proliferative mesenchymal cells bordering the fibrin and hemorrhage zone and differentiating toward immature cardiomyocytes. We further examined the heart explants at 5-days post-surgery (5D PO) and 1-week post-surgery (1W PO) to assess the repair progression. For the 0-day surgery piglets euthanized at 5D PO and 1W PO, half had abundant proliferating mesenchymal cells, suggesting active regeneration, while the other half showed increased extracellular collagen. The seven-day surgery piglets euthanized at 5D PO, and 1W PO showed evidence of greatly increased extracellular collagen, while some piglets had proliferating mesenchymal cells, suggesting a regenerative effort is ongoing while scar formation seems to predominate. In short, our qualitative findings suggest that the piglets lose the full myocardial regenerative potential by 7 days after birth, but greatly preserve the regenerative potential within 1 day post-partum.
