Functional vagal paraganglioma developing 15 years after resection of a retroperitoneal paraganglioma

The patient, a 40-year-old woman, was diagnosed as having a functional right vagal paraganglioma (PGL) 15 years after undergoing resection for a retroperitoneal PGL. 123I-MIBG scintigraphy showed no accumulation, but as the blood noradrenaline and urinary normetanephrine concentrations were elevated, the tumor was judged as being functional, and surgery was scheduled. The patient was started on doxazosin infusion and embolization of the tumor feeding vessel was performed before the surgery. Intraoperative examination showed that the tumor was contiguous with the vagal nerve, necessitating combined resection of the vagal nerve with the tumor. Postoperatively, the catecholamine levels returned to normal range. Histopathologically, the tumor was diagnosed as a moderately differentiated, intermediate-malignant-grade PGL, with a GAPP score of 4 to 6. No non-chromaffin tissue was observed in the tumor background, so that the functional vagal PGL was considered as a sporadic metachronous tumor rather than as a metastasis from the retroperitoneal PGL. More than half of head and neck paragangliomas (HNPGLs) are reported to arise in the carotid body, and about 5% from the vagal nerve. In addition, HNPGLs rarely produce catecholamines. Herein, we consider the relationship with the previously resected retroperitoneal PGL based on a review of the literature.

Diagnostic utility of cytology in a patient with Epstein-Barr virus-positive mucocutaneous ulcer in palatine tonsils: A case report

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a newly established immunodeficiency-related disease. Herein, we report a case of EBVMCU and focus on its cytological usefulness for diagnosis. An 82-year-old man manifested pharyngalgia, dysphagia, and oral pain. His medical history included rheumatoid arthritis that had been treated with methotrexate. Clinically, peritonsillar abscess was suspected, but since neoplastic lesions, including malignant lymphoma (ML), could not be excluded, a series of cytohistological examination was attempted. Despite some alarming findings (e.g., frequent mitoses), fine-needle aspiration and touch imprint cytology consistently revealed a heterogeneous population of lymphoid and plasmacytoid cells with mild nuclear atypia. The final diagnosis of EBVMCU was established based on the permanent histologic specimen; however, retrospectively, cytology was more representative of the benign nature of the lesion than histology, helping a great deal to differentiate it from ML. Cytology can be a useful tool for the correct diagnosis of EBVMCU.

Post-intubation laryngeal injury after COVID-19 treatment causing dyspnea: A report of six cases

Severe cases of COVID-19 often require orotracheal intubation (OTI) and mechanical ventilation, and post-intubation laryngeal injury (PI-LI) is one of the important complications of OTI. Some studies have claimed that the frequency of PI-LI may be higher in COVID-19 patients as compared with that in non-COVID-19 patients, because of the larger size of endotracheal tube used, the longer OTI time, use of prone positioning of the patients, etc. Herein, we describe six cases of PI-LI who presented with dyspnea after recovering from COVID-19. Five of the patients were male and the median OTI period was 9 days. All the patients showed abnormal endoscopic findings, including posterior glottic synechiae/stenosis or subglottic/posterior glottic granulomas. Four patients required surgical intervention, including tracheostomy, laryngomicrosurgery, or laterofixation of the vocal cord. Many post-COVID-19 patients experience persistent symptoms (post-COVID-19 syndrome), including dyspnea. Two of our patients with dyspnea had been treated by internists as cases of post-COVID-19 syndrome. Therefore, we wish to underscore the need for every healthcare professional to be aware of the possibility of PI-LI after OTI, especially during the ongoing COVID-19 pandemic. Otolaryngologists should undertake endoscopic assessment of the larynx in patients presenting with dyspnea after recovering from COVID-19.

Graphene delamination from chemical vapor deposited turbostratic multilayer graphene for TEM analysis

Turbostratic multilayer graphene (MLG) is of great interest due to its unique electronic properties resulting from a linear band dispersion at the K point, which is similar to that of single-layer graphene. The band structure is derived from the stacking structure of turbostratic MLG where graphene layers have random in-plane rotations with respect to each other. Although wafer-scale growth of turbostratic MLG has been demonstrated, the crystallinity of individual graphene layers is still challenging to investigate. In this study, we present a new approach to reveal the grain structure of turbostratic MLG by transmission electron microscopy (TEM) observation. Mechanical delamination is demonstrated for the chemical vapor deposited MLG to peel off the topmost graphene layers by using a polydimethylsiloxane sheet. Micrometer-scale patterning of the MLG prior to the delamination is found to be effective to obtain graphene films with the designed shape and arrangement. Furthermore, the delaminated graphene films are successfully transferred onto a TEM grid, enabling us to estimate the grain size of the turbostratic MLG. This method is potentially applicable for not only preparing samples but also fabricating vertically stacked heterostructure devices using 2D materials.

Screening of diabetes of youth for hepatocyte nuclear factor 1 mutations: clinical phenotype of HNF1β-related maturity-onset diabetes of the young and HNF1α-related maturity-onset diabetes of the young in Japanese

AIM

To compare the prevalence and clinical features of HNF1β-related MODY and HNF1α-related MODY in Japanese.

METHODS

We enrolled 230 Japanese patients with suspected MODY and examined them for HNF1α and HNF1β mutations. We characterized the clinical features of HNF1β-related MODY (HNF1β-MODY) and HNF1α-related MODY (HNF1α-MODY).

RESULTS

Six patients had HNF1β mutations, four of which were large gene deletions and 24 patients had HNF1α mutations, which included one gene deletion. The mean fasting plasma glucose level at onset of HNF1β-MODY was considerably higher and the age of onset of HNF1β-MODY was considerably older than they were for HNF1α-MODY, while the mean BMI and C-peptide index at onset were similar. Three patients with HNF1β-MODY were found to have dorsal pancreatic agenesis and four of them had whole-gene deletion. Five of the patients with HNF1β-MODY had insulin secretion defects and were treated with insulin, and four of these did not have a parent with overt diabetes.

CONCLUSION

HNF1β-MODY may present as β-cell dysfunction in Japanese rather than as hyperinsulinaemia, which it does among European/American. This dysfunction might result from an intrinsically lower capacity for insulin secretion in Japanese. HNF1β-MODY has an older age of onset than HNF1α-MODY, which may suggest lower penetrance of the disease. In addition, HNF1β-MODY has a broad spectrum of clinical manifestations, some of which are detectable by imaging. This may be helpful in some cases for selecting HNF1β-MODY candidates for genetic testing.

Intercellular adhesion molecule-1 expression on human corneal epithelial outgrowth from limbal explant in culture

AIM

To investigate the relation between intercellular adhesion molecule (ICAM)-1 expression and cellular dynamics occurring concomitantly with epithelial cell movement.

METHODS

Outgrowing epithelial sheets of human corneal epithelial (HCE) cells from cultured limbal explants were examined by immunoperoxidase staining with anti-ICAM-1 monoclonal antibody. An adhesion assay was performed using the epithelial sheets of HCE cells and an Epstein-Barr virus (EVB) infected B cell lymphoma cell line (EVB(+)BJAB) expressing CD11a/CD18, a counter-receptor of ICAM-1. Also, the effect of calphostin C, a specific protein kinase C (PKC) inhibitor, on ICAM-1 expression on the outgrowing epithelial sheets of HCE cells was examined.

RESULTS

Strong positive staining for ICAM-1 was found predominantly on HCE cells in the marginal segment of the epithelial sheet, particularly on the cells at the leading edge. EBV(+)BJAB cells adhering to the HCE cells corresponded well to the area of ICAM-1 staining. Treatment of outgrowing epithelial sheets with calphostin C markedly decreased the ICAM-1 expression on the HCE cells.

CONCLUSION

ICAM-1 is actively expressed on HCE cells in the marginal segment of the outgrowing epithelial sheets where there is active movement mediated through a PKC dependent mechanism, suggesting the role of ICAM-1 in epithelial cell motility such as the spreading and migration of cells.

Effects of amino acid replacements around the reactive site of chicken ovomucoid domain 3 on the inhibitory activity toward chymotrypsin and trypsin

We have previously shown that replacing the P1-site residue (Ala) of chicken ovomucoid domain 3 (OMCHI3) with a Met or Lys results in the acquisition of inhibitory activity toward chymotrypsin or trypsin, respectively. However, the inhibitory activities thus induced are not strong. In the present study, we introduced additional amino acid replacements around the reactive site to try to make the P1-site mutants more effective inhibitors of chymotrypsin or trypsin. The amino acid replacement Asp-->Tyr at the P2' site of OMCHI3(P1Met) resulted in conversion to a 35000-fold more effective inhibitor of chymotrypsin with an inhibitor constant (K(i)) of 1. 17x10(-11) M. The K(i) value of OMCHI3(P1Met, P2'Ala) indicated that the effect on the interaction with chymotrypsin of removing a negative charge from the P2' site was greater than that of introducing an aromatic ring. Similarly, enhanced inhibition of trypsin was observed when the Asp-->Tyr replacement was introduced into the P2' site of OMCHI3(P1Lys). Two additional replacements, Asp-->Ala at the P4 site and Arg-->Ala at the P3' site, made the mutant a more effective inhibitor of trypsin with a K(i) value of 1. 44x10(-9) M. By contrast, Arg-->Ala replacement at the P3' site of OMCHI3(P1Met, P2'Tyr) resulted in a greatly reduced inhibition of chymotrypsin, and Asp-->Ala replacement at the P4 site produced only a small change when compared with a natural variant of OMCHI3. These results clearly indicate that not only the P1-site residue but also the characteristics, particularly the electrostatic properties, of the amino acid residues around the reactive site of the protease inhibitor determine the strength of its interactions with proteases. Furthermore, amino acids with different characteristics are required around the reactive site for strong inhibition of chymotrypsin and trypsin.

Aspzincin, a family of metalloendopeptidases with a new zinc-binding motif. Identification of new zinc-binding sites (His(128), His(132), and Asp(164)) and three catalytically crucial residues (Glu(129), Asp(143), and Tyr(106)) of deuterolysin from Aspergillus oryzae by site-directed mutagenesis

Deuterolysin (EC 3.4.24.39; formerly designated as neutral proteinase II) from Aspergillus oryzae, which contains 1 g atom of zinc/mol of enzyme, is a single chain of 177 amino acid residues, includes three disulfide bonds, and has a molecular mass of 19,018 Da. Active-site determination of the recombinant enzyme expressed in Escherichia coli was performed by site-directed mutagenesis. Substitutions of His(128) and His(132) with Arg, of Glu(129) with Gln or Asp, of Asp(143) with Asn or Glu, of Asp(164) with Asn, and of Tyr(106) with Phe resulted in almost complete loss of the activity of the mutant enzymes. It can be concluded that His(128), His(132), and Asp(164) provide the Zn(2+) ligands of the enzyme according to a (65)Zn binding assay. Based on site-directed mutagenesis experiments, it was demonstrated that the three essential amino acid residues Glu(129), Asp(143), and Tyr(106) are catalytically crucial residues in the enzyme. Glu(129) may be implicated in a central role in the catalytic function. We conclude that deuterolysin is a member of a family of Zn(2+) metalloendopeptidases with a new zinc-binding motif, aspzincin, defined by the "HEXXH + D" motif and an aspartic acid as the third zinc ligand.

[Histological and ultrastructural study of corneal endothelium after excimer laser ablation in rabbit]

To investigate the effect of excimer laser ablation on the corneal endothelium in the early period, an excimer laser ablation was performed on rabbit cornea. Electron microscopy revealed an irregular space in the endothelial membrane facing Descemet's membrane 48 hours after the laser ablation. At 60 hours, electron-dense material was observed between the endothelial cells and Descemet's membrane. At 72 hours, electron-dense material was observed in Descemet's membrane, but no morphologic change was observed in the endothelium. These results suggest that excimer laser ablation may affect reversible corneal endothelium and it is important to perform a long-term follow-up of the corneal endothelium after excimer laser ablation in humans.

[Pseudo-Bartter syndrome without hypopotassemia: a case with unilateral multicystic dysplastic kidney and congenital contralateral hyronephrosis]

A 2-month-old girl having a left multicystic dysplastic kidney with contralateral mild hydronephrosis is described. Furosemide was administered orally because of hyperpotassemia during the period between 1 month and 7 months of age. Peripheral plasma renin activity and plasma aldosterone activity increased at the age of 6 months, and ultimately reached the peak at 9 days after discontinuation of furosemide at the age of 7 months. Peripheral plasma renin activity and plasma aldosterone activity were normalized at the age of 11 months. Blood pressure during the whole period was normal. Contralateral hydronephrosis was improved gradually. The level of serum creatinine became normal at the age of 50 days. A case with a high level of plasma renin and aldosterone activity temporarily induced by furosemide was reported. Pathophysiology of pseudo-Bartter syndrome without hypopotassemia due to furosemide is discussed.

Secretory production of chicken ovomucoid domain 3 by Escherichia coli and alteration of inhibitory specificity toward proteases by substitution of the P1 site residue

Ovomucoids are commonly present in bird egg white and exhibit inhibitory activity toward various serine proteases. To investigate the structure-function relationship of ovomucoid domain 3, we established a secretory expression system for the chicken ovomucoid domain 3 (OMCHI3)-encoding gene in Escherichia coli by ligating it downstream from the tac promoter and signal peptide of E. coli alkaline phosphatase. E. coli JM105 was transformed with the resulting plasmid and induced with 1 mM isopropyl-beta-D-thiogalactopyranoside (IPTG). The mature OMCHI3 was detected in the culture supernatant, and was purified to homogeneity by three-step chromatography. Amino-acid sequence analysis showed that processing by the signal peptidase was carried out exactly at the expected site. Measurements of circular dichroism spectra and inhibitory activity indicated that OMCHI3 was produced in the properly folded form. Furthermore, site-specific replacement of the Ala residue at the P1 site with Met or Lys resulted in acquisition of inhibitory activity toward chymotrypsin or trypsin, respectively, indicating that the P1 site is the predominant determinant for inhibitory specificity.

[A case of male pseudohermaphroditism with structural abnormalities of Y chromosome (ring Y)]

A case of male pseudohermaphroditism with ring Y chromosome is reported. The patient was a 3-year-old boy with hypospadias and right cryptorchidism. Culture of peripheral lymphocytes demonstrated a chromosomal mosaicism of 45 X/46 X, r (Y). Moreover, the chromosomal study with high resolution Q-band method revealed the presence of double ring Y (ring Y and double ring Y with the ratio of 25: 5). A well-developed vagina was discovered by retrograde cystourethrography. Uterus and fallopian tubes were absent at exploratory laparotomy. The gonads existed in the scrotum on the left side and in the inguinal pouch on the right. Both gonads were proved to be testes histologically, but bilateral was deferens were absent and its remnant was found in the retroperitoneal cavity. Plastic surgery for the genital abnormalities was performed. Only 30 cases of ring Y chromosome have been reported in the world including our case and we briefly reviewed these cases.

[A case of mixed gonadal dysgenesis with structural abnormalities of X chromosome (Xp+)]

An abnormal extra band on the short arm of the X chromosome was found in a 7-year-old reared as a female, of mixed gonadal dysgenesis. She had ambiguous external genitalia, scoliosis, short stature, mental retardation and motor paralysis of the limbs. Chromosomal analysis revealed the karyotype of 46,Xp+ Y. An uterus with fallopian tube, a streak gonad on the left side and a testicle on the right side were discovered at exploratory laparotomy. Bilateral gonads and fallopian tube were removed. The chromosomal analysis of her normal mother showed the presence of the same abnormal X chromosome (46, X Xp+). In the literature, we found some cases of intersexuality with Xp+ in karyotype. The relationship between our own case and these Xp+ cases was discussed briefly. Thirty-five cases of mixed gonadal dysgenesis have been reported in Japanese literature, our own case being the 36th case.

[Clinical evaluation of serum ferritin levels in urologic cancer (II)]

By means of the RIA-Gnost Ferritin and Spac Ferritin kits, the serum ferritin levels of patients with some urological malignant diseases were quantitated; and, the clinical significance of these values as a tumor marker was discussed. The normal (reference) level in serum obtained by the RIA-Gnost kit was 142.5 +/- 67.5 ng/ml (n = 58) for healthy males and 49.6 +/- 28.8 ng/ml (n = 76) for healthy females. The assay values for 22 cases of bladder cancer by both kits were somewhat lower than the normal range, and the positive rates presented were around 30%, being in rough agreement with each other. The positive rate for 22 patients with prostatic cancer was 45.5% by either method. The assay values obtained by the RIA-Gnost kit was higher and differed significantly (p less than 0.1%) from those obtained on healthy males. Furthermore, the same tendency was found in 6 cases of renal cancer. The assay values of RIA-Gnost were significantly higher (p less than 0.1%) than normal; and, the positive rate was 100% for RIA-Gnost and 67% for Spac . In conclusion, serum ferritin determination especially that by the RIA-Gnost kit proved to be a useful and significant tumor marker for the detection of renal cancer.

Humoral immunity following double-freezing of the prostate in patients with prostatic cancer

In these studies, 10 patients with a confirmed histological diagnosis of stage C and D carcinoma underwent double-freezing of the prostate. The clinical courses in the first group (five patients) were favorable. In the second group (two patients), death by cachexia occurred due to the cancer. In the third group (three patients), death 4 weeks after the second cryosurgery suggests the effects of cryoshock. In the first and second groups, the results of the immunological examinations after the second freezing did not attain the predicted levels. Comparing the results of the third group with those of the first and second groups the primary differences was that the percentages of gamma-globulins and IgE were higher in the third group preoperatively. These findings suggest that patients with high percentages of gamma-globulin and high IgE levels are contraindicated for cryosurgery of the prostate.

Effect of cryosurgery of the prostate in serum gonadotropin levels in prostatic cancer

Pituitary gland response to releasing hormone using the LH-RH loading test before and 4 weeks after cryosurgery of the prostate was investigated in eight patients with advanced prostatic carcinoma. In pre- and postoperative comparisons of all patients, there were no significant differences detected before and after surgery. But pituitary response to the releasing hormone was compared before and after the surgery in each of the patients; in one, depression and facilitation of FSH and LH secretion, respectively, were observed and there was a variation in the response of gonadotropin in each patient. Although the number of observable patients is still too low to draw any definite conclusions from the test results, one possible interpretation is that cryosurgery of the prostate may influence hormonal secretion from the pituitary gland.