Contrast-enhanced ultrasound findings in testicular torsion and non-testicular torsion.

PURPOSE: Testicular torsion requires emergency surgery; thus, prompt and correct diagnosis is very important. Ultrasound with color Doppler is usually the first-choice modality for diagnosis; however, skill and experience are required for confident diagnosis. Recently, contrast-enhanced ultrasound for the diagnosis of testicular torsion has been reported, but there have been only a few reports. This study aimed to compare contrast-enhanced ultrasound findings in cases of testicular torsion and non-testicular torsion. METHODS: Patients who underwent contrast-enhanced ultrasound for acute scrotum at our institution between April 2010 and January 2023 were divided into testicular torsion (n = 17) and non-testicular torsion (n = 16) groups. The respective contrast-enhanced ultrasound findings were retrospectively examined and compared. RESULTS: In 16 out of 17 cases of testicular torsion, the parenchyma of the affected testis was not enhanced. In the remaining case, reduced contrast enhancement was observed; however, it was still notably less than that observed on the unaffected testis. On the other hand, in all cases of non-testicular torsion (n = 16), the parenchyma of the affected testis was notably enhanced. CONCLUSION: Contrast-enhanced ultrasound is considered an easy and accurate method for diagnosing testicular torsion.

Infantile type I pleuropulmonary blastoma presenting with dyspnea due to compression by pneumothorax and an occupying tumor: a case report.

BACKGROUND: Pleuropulmonary blastoma (PPB) is an extremely rare and malignant pediatric lung tumor. Purely cystic PPB has a more favorable prognosis than solid PPB, but may be difficult to distinguish from a certain type of "benign" congenital pulmonary airway malformation before and during surgery. The influence of tumor rupture on long life prognosis has not been clarified in detail. CASE PRESENTATION: A 5-month-old boy underwent emergency transfer from another hospital due to a left thoracic cystic lesion and left pneumothorax detected on chest radiography performed for persistent wheeze and cough. Contrast-enhanced computed tomography of the chest revealed marked deviation of the mediastinum to the right due to a giant cystic lesion and pneumothorax. Thoracotomy was performed on hospital day 2. A cystic lesion had developed from the distal alveolar region of lower lobe of the left lung and the tumor showed a tiny adhesion to the left diaphragm and a tiny rupture near the adhesion. Partial lung excision including the cyst and scraping of the adhesion were performed. Histopathological investigations revealed immature blast cell-like mesenchymal cells and differentiated striated muscle cells in a dense cambium layer were found under the epithelium of the cystic lesion. Type I PPB was diagnosed. CONCLUSIONS: Surgery should be performed with the possibility of type I PPB in mind when an extrapulmonary cystic lung lesion is found. Since issues such as the pathogenesis and long-term prognosis of ruptured cases remain unclear, continued careful follow-up of this case will be required.

Challenging management of a baby with congenital multiple intestinal atresia, trisomy 18 and extremely low birth weight: a case report.

BACKGROUND: Extremely low birth weight (< 1000 g) still influences postsurgical prognosis in the neonatal and infantile periods. Additionally, the life expectancy of neonates with trisomy 18 is extremely poor owing to various comorbidities. Therefore, it takes courage to perform laparotomy for the purpose of treatment of congenital multiple intestinal atresia in a baby with an unpredictable life prognosis. CASE PRESENTATION: Fetal ultrasonography revealed cardiac malformation, intestinal dilation, and physical characteristics suggestive of a chromosomal abnormality in this case. The patient was diagnosed with trisomy 18 after birth, with an extremely low birth weight. An atrial septal defect, ventricular septal defect, dilated jejunum, and a very thin collapsed small intestine were found on ultrasonography. With a diagnosis of congenital small intestinal atresia, a challenging laparotomy was done at 3 days of age, with jejunal atresia and multiple distal small intestinal atresia were observed. The jejunal end and distal small intestinal stump were separated into stomas at the wound edge. Hypertrophic pyloric stenosis developed at the age of 3 months and resolved with medication. The patient gained weight (2 kg) by daily stool injection into anal side of the intestine and decompression against poor peritonitis of dilated jejunum using enteral feeding tube for the long period. Finally, we could perform intestinal reconstruction safely and successfully at the age of 9 months. Tracheotomy was performed due to difficulty in extubation associated with chronic lung disease. The patient was discharged at the age of 1 year and 3 months, and no major problems were noted at the age of 2 years. CONCLUSIONS: We treat congenital intestinal atresia in extremely low birth weight infants with severe chromosomal abnormalities and severe cardiac malformations as follows: Stoma creation is performed quickly to avoid deterioration of the patient's hemodynamics. After that, while continuing enteric management, palliative cardiovascular surgery is performed as necessary, and the patient's body weight and intestinal tract status are determined to allow safe intestinal reconstruction.

Neonatal necrotizing fasciitis with gas gangrene due to peripherally inserted central catheter-related infection.

BACKGROUND: Necrotizing fasciitis in neonates is a rare and life-threatening infection involving necrosis of the skin, subcutaneous tissues, deep fascia, and sometimes underlying muscles, with a fulminant course and high mortality rate. Necrotizing fasciitis with gas gangrene related to infection of a peripherally inserted central catheter is very rare. CASE PRESENTATION: The patient was a full-term female neonate born by vaginal delivery. Following diagnosis of patent ductus arteriosus, indomethacin was administered from a peripherally inserted central catheter for 3 days. Four days after the termination of medical treatment for the patent ductus arteriosus, the patient developed fever and a severely elevated inflammatory response was identified from blood testing. Around the right anterior chest wall, corresponding to the site of the catheter tip, redness was increased and gas crepitus was felt under the skin. Computed tomography revealed emphysema in the anterior chest, in subcutaneous areas and between muscles. Emergency surgical debridement was performed under a diagnosis of necrotizing fasciitis with gas gangrene. With antibiotic treatment, we started to fill the wound with a dialkyl carbamoyl chloride-coated dressing and povidone-iodine sugar ointment after washing with saline once a day. The patient survived and after 3 weeks of treatment with the dressing, the wound had successfully resolved without motor impairments. CONCLUSIONS: In addition to medical treatment and prompt surgical debridement, we used dialkyl carbamoyl chloride-coated dressing and povidone-iodine sugar ointment for antiseptic dressings and successfully treated neonatal necrotizing fasciitis with gas gangrene caused by peripherally inserted central catheter infection with Citrobacter koseri.

Axillary skin crease incision versus conventional posterolateral incision in open repair of patent ductus arteriosus for extremely low birth weight infants: a retrospective study.

BACKGROUND: Thoracotomy with posterolateral incision (PLI) is commonly used for surgical repair of patent ductus arteriosus (PDA) in extremely low birth weight (ELBW) infants. Some reports have described thoracotomy for PDA using an axillary skin crease incision (ASCI) in consideration of cosmetic problems such as surgical wounds and thoracic deformities, but the details remain unclear. METHODS: In this study, we performed clipping ligation by thoracotomy with ASCI for ELBW infants with PDA from 2011 to 2015 for the purpose of improving cosmetic results, and retrospectively compared the results with those for conventional PLI cases performed from 2016 to 2020. RESULTS: ASCI was found to be associated with serious surgical complications and showed a significant difference in outcome parameters only for surgery time, suggesting a safety problem for ASCI. Considering these results, PLI allows clipping of the nearby PDA from the thoracotomy wound while looking straight ahead, whereas the PDA in ASCI is positioned deep and oblique to the thoracotomy wound, so the clipping angle is limited and accurate completion of the procedure is difficult. CONCLUSIONS: Regarding PDA repair in ELBW infants, ASCI shows a high risk of serious surgical complications. Conventional PLI remains preferable for safe and accurate results.

Increased RET Activity Coupled with a Reduction in the RET Gene Dosage Causes Intestinal Aganglionosis in Mice.

Mutations of the gene encoding the RET tyrosine kinase causes Hirschsprung's disease (HSCR) and medullary thyroid carcinoma (MTC). Current consensus holds that HSCR and MTC are induced by inactivating and activating RET mutations, respectively. However, it remains unknown whether activating mutations in the RET gene have adverse effects on ENS development in vivo We addressed this issue by examining mice engineered to express RET51(C618F), an activating mutation identified in MTC patients. Although Ret51(C618F)/51(C618F) mice displayed hyperganglionosis of the ENS, Ret51(C618F)/- mice exhibited severe intestinal aganglionosis because of premature neuronal differentiation. Reduced levels of glial cell-derived neurotrophic factor (GDNF), a RET-activating neurotrophic factor, ameliorated the ENS phenotype of Ret51(C618F)/- mice, demonstrating that GDNF-mediated activation of RET51(C618F) is responsible for severe aganglionic phenotype. The RET51(C618F) allele showed genetic interaction with Ednrb gene, one of modifier genes for HSCR. These data reveal that proliferation and differentiation of ENS precursors are exquisitely controlled by both the activation levels and total dose of RET. Increased RET activity coupled with a decreased gene dosage can cause intestinal aganglionosis, a finding that provides novel insight into HSCR pathogenesis.

Mice conditionally expressing RET(C618F) mutation display C cell hyperplasia and hyperganglionosis of the enteric nervous system.

Medullary thyroid carcinoma (MTC) develops from hyperplasia of thyroid C cells and represents one of the major causes of thyroid cancer mortality. Mutations in the cysteine-rich domain (CRD) of the RET gene are the most prevalent genetic cause of MTC. The current consensus holds that such cysteine mutations cause ligand-independent dimerization and constitutive activation of RET. However, given the number of the CRD mutations left uncharacterized, our understanding of the pathogenetic mechanisms by which CRD mutations lead to MTC remains incomplete. We report here that RET(C618F), a mutation identified in MTC patients, displays moderately high basal activity and requires the ligand for its full activation. To assess the biological significance of RET(C618F) in organogenesis, we generated a knock-in mouse line conditionally expressing RET(C618F) cDNA by the Ret promoter. The RET(C618F) allele can be made to be Ret-null and express mCherry by Cre-loxP recombination, which allows the assessment of the biological influence of RET(C618F) in vivo. Mice expressing RET(C618F) display mild C cell hyperplasia and increased numbers of enteric neurons, indicating that RET(C618F) confers gain-of-function phenotypes. This mouse line serves as a novel biological platform for investigating pathogenetic mechanisms involved in MTC and enteric hyperganglionosis.

Strategy for surgical treatment of congenital subglottic stenosis in children.

BACKGROUND/PURPOSE: Congenital subglottic stenosis is a rare anomaly caused by thickened cricoid cartilage. We report our surgical techniques, comprising anterior cricoid split (ACS), laryngotracheoplasty (LTP), KTP laser ablation, and application of a tracheal opening retainer (TOR) into the tracheostomy site. METHODS: Nine patients have been treated since 1988. Four patients (median age 85 days; range 5 days to 6 months) underwent ACS. Another four patients (median age, 17 months; range, 5-57 months) underwent LTP using costal cartilage grafts, although two had undergone tracheostomy before LTP. One patient underwent LTP, ablation of the projecting part of the cricoid cartilage with KTP laser (LTP + Laser) and, preservation of the tracheal opening by placement of the TOR. RESULTS: All ACS and LTP patients were successfully extubated at a median of 32 days (range 23-91 days) and 23 days (range 6-31 days) postoperatively, respectively. The LTP + Laser patient was extubated 35 days after surgery and the TOR was removed asymptomatically 20 days after extubation of the stent tube. CONCLUSIONS: Anterior cricoid split is useful for patients ≤ 6 months old and LTP is useful for patients >6 months old and/or with tracheostomy. KTP laser ablation is effective to remove thickened parts of cricoid cartilage protecting the vocal cords. The tracheal opening preserved by the TOR works as an additional channel to safeguard respiration during the extubation process.

FGF2 triggers iris-derived lens regeneration in newt eye.

Lens regeneration in newts occurs exclusively from the dorsal aspect of the iris pigment epithelium. Although the phenomenon has been a paradigm of experimental tissue regeneration, little is understood about how it is initiated and restricted to the dorsal iris. Here we show among various growth factors injected in an intact eye, a single injection of FGF2 specifically caused morphological changes of the iris characteristic of lens regeneration, induced expression of transcription factor genes Pax6, Sox2 and MafB, as well as endogenous Fgf2 in both dorsal and ventral halves, and provoked second lens development only from the dorsal iris. FGF2 protein accumulated in the iris tissue after the lens was removed, and injection of a soluble form of FGF receptor titrating FGF2 inhibited all reactions observed after the lens removal or after administration of FGF2. These results indicate that FGF2 and/or related molecules trigger lens regeneration from the dorsal iris in the newt. The observations also indicate that the absence of lens regeneration from the ventral iris is due to a block in a later phase of lens developmental pathway.

Regulated lens regeneration from isolated pigmented epithelial cells of newt iris in culture in response to FGF2/4.

When a lens is removed from the newt eye, a new lens is regenerated from the pigmented epithelial cells of the dorsal iris, whereas the ventral iris never shows such an ability. It is important to clarify the nature of signaling molecules which act directly on the iris cells to accomplish lens regeneration from the iris and also to gain insight into the mechanism of dorso-ventral difference of the regeneration potential. To examine the effects of exogenous factors, we established an in vitro culture of reaggregates made from dissociated pigmented epithelial cells of dorsal or ventral halves of newt iris. Foci of depigmented cells appeared within the cell reaggregates, regardless of their origins, when the cell reaggregates were cultured with FGF2 or FGF4. In contrast, only the depigmented cells in the dorsal iris cell reaggregates underwent extensive proliferation and developed a lens with the synthesis of lens-specific crystallins, recapitulating the normal lens regeneration. On the other hand, neither FGF8, FGF10, EGF, VEGF, nor IGF promoted lens development from iris cell reaggregates. Consistent with the FGF-specific action, FGFR-specific inhibitor SU5402 suppressed the lens development from the cultured cell reaggregates. These results demonstrated that FGF2 or FGF4 is essential for the in vitro lens regeneration from the pigmented cells of the dorsal iris. In addition, these findings indicated that unequal competence in the dorsal and ventral iris to FGF2/4 contributes to the difference in lens forming ability between them.

Inhibition of Lens Regeneration by Nickel Subsulfide in the Japanese Common Newt, Cynops pyrrhogaster: (newt/lens regeneration/nickel subsulfide/carcinogenesis).

To investigate the effects of nickel subsulfide (Ni3 S2 ) on lens regeneration, Ni3 S2 was administered to the lentectomized newt eye by a single injection into the eye chamber. Lens regeneration was inhibited in the early stage of regeneration with about 60% of the treated eyes after 25 days, while all control eyes had a regenerating lens. The size of the regenerating lens in the treated eyes was the same as in controls. Lens regeneration was inhibited in all treated eyes containing Ni3 S2 particles within the eye chamber. Inhibition of lens regeneration in the treated eyes was about 80% at 3 months, when all control eyes had already completed lens regeneration. Although the tendency toward pupil disappearance was prominent in the eyes having no regenerating lens, there were also a few eyes which had no regenerating lens and no signs of pupil disappearance. The significance of these results was discussed in relation to the regeneration and carcinogenesis.