Inhibin B regulating follicle-stimulating hormone secretion during testicular recrudescence in the male golden hamster

In the present study, to clarify whether inhibin affects follicle-stimulating hormone (FSH) secretion in the recrudescence of the male golden hamster, we used a recently developed specific enzyme-linked immunosorbent assay (ELISA) in order to measure 2 forms of inhibin molecules: inhibin B and inhibin pro-alphaC. In addition, we used the radioimmunoassay (RIA) to measure immunoreactive (ir-)inhibin, FSH, luteinizing hormone (LH), and testosterone. And finally, we used the proliferating cell nuclear antigen (PCNA) and computer-assisted sperm motion analysis (CASA) methods to ascertain how well spermatogenesis and sperm motility recover from the photoinhibition caused by exposure to a short-day (SD; 10-hour light: 14-hour dark) photoperiod. Animals were exposed to SD for 15 weeks, and then their testes were checked carefully and found to be completely regressed. Thereafter, those animals were transported to a long-day (LD; 14-hour light: 10-hour dark) photoperiod. Sampling was carried out at weeks 0 (exposed SD 15 weeks), 1, 2, 4, 6, 8, and 10. Plasma FSH rapidly increased and reached peak levels 2 weeks after transferral to the LD photoperiod and then declined to normal LD levels at week 6. Circulating ir-inhibin, inhibin B, and inhibin pro-alphaC rose to normal LD levels by week 4. A highly significant inverse correlation was observed between plasma FSH and inhibin B but not between FSH and either ir-inhibin or inhibin pro-alphaC. Plasma testosterone recovered to normal LD levels within 1 week. Sperm motility parameters were low until week 2 and recovered to normal LD levels from weeks 4 to 10. PCNA-labeled cells were confined to the spermatogenic cells of the seminiferous tubules, though Leydig and Sertoli cell nuclei were never stained for PCNA during the period studied. The number of pachytene spermatocytes and the diameter of seminiferous tubules increased in a time-dependent manner after transferral from SD to LD. In conclusion, these results suggest that 1) secretion of inhibin B may be stimulated by an early rise in FSH; 2) inhibin B suppresses FSH secretion from weeks 2 to 10, after transferral to the LD photoperiod; and 3) testes recrudescence is based on the increase in the number of sperm cells instead of the increase in the number of Sertoli and Leydig cells of the male golden hamster.     

Anesthesia protocols for early vitrectomy in former preterm infants diagnosed with aggressive posterior retinopathy of prematurity

Aggressive posterior retinopathy of prematurity (ROP) can, if left untreated, rapidly progress to total retinal detachment within 1–2 weeks. Early surgical intervention with vitrectomy has been attempted to treat and prevent further retinal detachment. We investigated the anesthetic management of 29 infants with aggressive posterior ROP undergoing early vitrectomy. Postmenstrual age at surgery ranged from 35 to 47 weeks (median 41). Weight ranged from 1408 to 3478 g (median 1875). All infants underwent general anesthesia with fentanyl and sevoflurane. Mean surgical and anesthetic times were 88.6 and 143.6 min, respectively. In two patients, vitrectomy was postponed for one week due to enteric perforation in one patient and meningitis in the other, because the anticipated perioperative risk was deemed high. There were no intraoperative complications, except in one patient who developed pulmonary edema following upper airway obstruction. All patients survived to be discharged from NICU or transferred to the referring hospital. In all cases, complete or partial retinal reattachment was successfully achieved. Early vitrectomy for aggressive posterior ROP may be effective despite associated perioperative risks. As this condition progresses rapidly, prompt preoperative organization, including anesthetic planning, is important and useful. Anesthesiologists can play an important role in the perioperative management of such high-risk infants.     

Aberrant Gene Methylation in the Lymph Nodes Provides a Possible Marker for Diagnosing Micrometastasis in Gastric Cancer

Background  

This study was designed to determine whether gene methylation is a novel diagnostic marker for micrometastasis to the lymph nodes (LNs) in gastric cancer.     

Sentinel Lymph Node Detection in Breast Cancer Patients by Real‐Time Virtual Sonography Constructed With Three‐Dimensional Computed Tomography‐Lymphography

Abstract: Ultrasonography (US) is one tool for preoperative diagnosis of lymph node metastases in breast cancer. However, US cannot detect true sentinel lymph nodes (SLNs). We identified SLNs in 60 clinically node‐negative breast cancer patients using a real‐time virtual sonography (RVS) system to display in real time a virtual multi‐planar reconstruction obtained from computed tomography (CT) volume data corresponding to the same cross‐sectional image from US. CT volume data were obtained from our original three‐dimensional CT lymphography (3DCT‐LG), which accurately detects SLNs in breast cancer. SLN metastases were assessed by shape and visibility of the hilum. All patients underwent SLN biopsy and SLN metastases were examined pathologically. In all 60 patients, we were able to detect the same SLNs visualized by 3DCT‐LG. Suspicious SLN metastases were identified in seven of the 60 patients, and four of seven patients were pathologically positive. Positive predictive value was 57%. The remaining 53 patients displayed non‐suspect SLNs in which absence of metastasis from the SLN was confirmed histologically. Overall accuracy was 95%. This is a first attempt at preoperatively identifying SLNs using US guided by the RVS system in breast cancer patients. Although evaluation of SLN metastases was unsatisfactory, this method may be useful for preoperative fine‐needle aspiration cytology for diagnosis of SLN metastases.     

Functional assessment of canine kidneys after acute vascular occlusion on Gd-DTPA-enhanced dynamic echo-planar MR imaging

RATIONALE AND OBJECTIVES: To assess the alteration in renal transit of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) in dog kidneys after acute vascular occlusion on dynamic echo-planar imaging (EPI). METHODS: Dynamic 240-ms EPI series (repetition time/echo time/inversion time [TR/TE/TI] = 3000/42.1/100 ms) of the midcoronal plane of both kidneys of dogs anesthetized by intravenous administration of phenobarbital sodium and ketamine hydrochloride were obtained before and after ligation of the left renal vein (n = 6) or artery (n = 6) for 40 minutes after a 2-second-rate bolus injection of a 0.05 mmol/kg dose of Gd-DTPA. Renal Gd-DTPA transit was analyzed on the time-DeltaR2* curves in each layer of the outer cortex (OC), juxtamedullary cortex and outer zone of the medulla (JMC-OM), and the inner zone of the medulla (IM). The results were compared with those in six normal animals and those of a fast gradient-echo T1-weighted dynamic study performed in other vein- (n = 6) or artery- (n = 6) occluded animals and six normal animals. The histopathological basis of the altered Gd-DTPA transit was also evaluated. RESULTS: The dynamic EPI showed rapid Gd-DTPA transit through each of the five concentric layers, with three separate peaks on the time-DeltaR2* curves. The vein-occluded kidneys showed immediate swelling, with a significant increase in the cross-sectional area proportion of the JMC-OM layer compared with normals (32% +/- 2% vs 24% +/- 2%, P < 0.0001) and intensely congested capillaries, tubular, obliterated material, and gradual and persistent enhancement of the OC and JMC-OM layers but poor Gd-DTPA migration to the IM layer. The artery-occluded kidneys showed a significant reduction in the entire cross-sectional area compared with normals (1352 +/- 69 vs 1432 +/- 47 mm(2), P < 0.05) and poor enhancement, with significant decreases in the area under the time-DeltaR2* curve of the OC and JMC-OM layers compared with the vein-occluded kidneys (79 +/- 50 vs 324 +/- 108 and 82 +/- 42 vs 326 +/- 113, respectively; both P < 0.0001), despite minimal histological damage. In both models, the nonaffected kidneys showed significant increases in the area under the time-DeltaR2* curves compared with baseline. The time course of vascular and tubular Gd-DTPA transit was more detailed by the EPI study than by the T1-weighted imaging study. CONCLUSIONS: Echo-planar imaging has an excellent ability to follow the rapid, renal Gd-DTPA transit through the regional anatomy of the canine kidney. After venous occlusion, the JMC-OM layer may be the most affected site, primarily causing renal swelling and interruption of tubular Gd-DTPA transit and concentration. In contrast, an initial block of vascular Gd-DTPA inflow is the primary effect of arterial occlusion. Nonaffected kidneys seem to compensate by increasing excretion of Gd-DTPA.     

Neutralization of blood group A-antigen by a novel anti-A antibody: overcoming ABO-incompatible solid-organ transplantation

BACKGROUND: The major barrier to ABO-incompatible solid-organ transplantation is acute humoral rejection. It is known to be triggered by antidonor blood group A/B antibodies, which might bind to A/B-antigen on the endothelium of the graft. Various strategies to reduce antiblood group antibody by overcoming ABO-incompatible transplantation have been tried. However, antigen-suppressing procedures have not been performed. METHODS: We produced a novel anti-A antibody (K7508) by immunizing mice with salivary mucin of a blood group A individual, thereby clarifying that blood group A-antigen is expressed in endothelial cells of the liver. We investigated whether K7508 can mask A-antigen on the cells in vitro. Next, we immunized mice with A-antigen-expressing cells coated with K7508 or its Fab fragment, and measured anti-A antibody production in the mice. RESULTS: Blood group A-antigen-expressing cells, such as blood group A-red blood cells (A-RBCs) and A431 cells, coated with K7508 were not recognized by another anti-A antibody in flow cytometry, indicating that A-antigen was masked by K7508 in vitro. The A-antigen on the paraffin-embedded liver tissue was also masked by K7508. Furthermore, the production of anti-A antibody in mice immunized with A-antigen-expressing cells coated with K7508 or its Fab fragment was significantly suppressed compared to that in mice immunized with non-coated cells alone, indicating that A-antigen was neutralized by K7508 in vivo. CONCLUSIONS: The neutralization of blood group antigen by antiblood group antibody and especially its Fab fragment might represent one strategy to overcome ABO-incompatible organ transplantation.     

Regulation of osteoclast differentiation by fibroblast growth factor 2: stimulation of receptor activator of nuclear factor kappaB ligand/osteoclast differentiation factor expression in osteoblasts and inhibition of macrophage colony-stimulating factor function in osteoclast precursors.

This study investigated the mechanism of direct and indirect actions of fibroblast growth factor 2 (FGF-2) on osteoclast differentiation using two mouse cell culture systems. In the coculture system of osteoblasts and bone marrow cells, FGF-2 stimulated osteoclast formation. This effect was decreased markedly by osteoprotegerin (OPG) or NS-398, a selective cyclo-oxygenase 2 (COX-2) inhibitor. FGF-2 (> or = 10(-9) M) stimulated receptor activator of nuclear factor kappaB ligand/osteoclast differentiation factor (RANKL/ODF) messenger RNA (mRNA) expression from 2 h to 7 days in cultured osteoblasts. NS-398 did not affect the early induction but decreased the later one, indicating that the later effect is mediated by COX-2 induction in osteoblasts. To study the direct action of FGF-2 on osteoclast precursors, we used mouse macrophage-like cell line C7 cells that can differentiate into osteoclasts in the presence of soluble RANKL/ODF (sRANKL/ODF) and macrophage colony-stimulating factor (M-CSF). Although osteoblasts expressed all FGF receptors (FGFR-1 to -4), only FGFR-1 was detected in C7 cells at various differentiation stages. FGF-2 alone or in combination with sRANKL/ODF did not induce osteoclastogenesis from C7 cells; however, FGF-2 from lower concentrations (> or = 10(-11) M) significantly decreased osteoclast formation induced by M-CSF in the presence of sRANKL/ODF. FGF-2 did not alter mRNA levels of M-CSF receptor (Fms) or RANK in C7 cells. Immunoprecipitation/ immunoblotting analyses revealed that tyrosine phosphorylation of several cellular proteins including Fms in C7 cells induced by M-CSF was inhibited by FGF-2 in the presence of sRANKL/ODF. We conclude that FGF-2 regulates osteoclast differentiation through two different mechanisms: (1) an indirect stimulatory action via osteoblasts to induce RANKL/ODF partly through COX-2 induction and prostaglandin production and (2) a direct inhibitory action on osteoclast precursors by counteracting M-CSF signaling.     

Case in which landiolol hydrochloride improved left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve following mitral valve plasty

We report a case of left ventricular outflow tract (LVOT) obstruction caused by systolic anterior motion of the mitral valve (SAM) following mitral valve plasity (MVP). A 65-year-old man underwent mitral valve plasty for grade III mitral valve regurgitation. The plasty was done smoothly and the patient was weaned from cardiopulmonary bypass successfully with continuous dobutamine infusion. However, about 30 minutes after the weaning, severe cardiovascular collapse developed. Inotropic agent, such as dobutamine, ephedrine, or calcium hydrochloride was not effective. Trans-esophageal echocardiography (TEE) showed severe mitral valve regurgitation with LVOT obstruction due to SAM. The collapse was successfully treated with volume loading and a small amount of a beta1-adrenergic antagonist, landiolol hydrochloride. We conclude that acute LVOT obstruction with SAM could develop following MVP. TEE was a much useful tool for early diagnosis and landiolol hydrochloride would be a notable agent for nonsurgical treatment of LVOT obstruction with SAM.     

Gonadotropin-inhibitory hormone neurons interact directly with gonadotropin-releasing hormone-I and -II neurons in European starling brain

Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic dodecapeptide (SIKPSAYLPLRF-NH(2)) that directly inhibits gonadotropin synthesis and release from quail pituitary. The action of GnIH is mediated by a novel G-protein coupled receptor. This gonadotropin-inhibitory system may be widespread in vertebrates, at least birds and mammals. In these higher vertebrates, histological evidence suggests contact of GnIH immunoreactive axon terminals with GnRH neurons, thus indicating direct regulation of GnRH neuronal activity by GnIH. In this study we investigated the interaction of GnIH and GnRH-I and -II neurons in European starling (Sturnus vulgaris) brain. Cloned starling GnIH precursor cDNA encoded three peptides that possess characteristic LPXRF-amide (X = L or Q) motifs at the C termini. Starling GnIH was further identified as SIKPFANLPLRF-NH(2) by mass spectrometry combined with immunoaffinity purification. GnIH neurons, identified by in situ hybridization and immunocytochemistry (ICC), were clustered in the hypothalamic paraventricular nucleus. GnIH immunoreactive fiber terminals were present in the external layer of the median eminence in addition to the preoptic area and midbrain, where GnRH-I and GnRH-II neuronal cell bodies exist, respectively. GnIH axon terminals on GnRH-I and -II neurons were shown by GnIH and GnRH double-label ICC. Furthermore, the expression of starling GnIH receptor mRNA was identified in both GnRH-I and GnRH-II neurons by in situ hybridization combined with GnRH ICC. The cellular localization of GnIH receptor has not previously been identified in any vertebrate brain. Thus, GnIH may regulate reproduction of vertebrates by directly modulating GnRH-I and GnRH-II neuronal activity, in addition to influencing the pituitary gland.