A case of diaphragmatic hernia incarceration after a heart transplant operation

We report a case of a diaphragmatic hernia after a heart transplant operation. A 43-year-old woman, who underwent orthotropic heart transplantation for hypertrophic cadiomyopathy two year earlier, presented with vomiting and epigastric pain. A computed tomography scan showed that the stomach and transverse colon were dislocated in the left thoracic cavity. We diagnosed left diaphragmatic hernia incarceration and performed laparoscopic repair of the diaphragmatic hernia. A 12 × 8 cm diaphragmatic defect was found intraoperatively on the ventrolateral aspect of the left diaphragm, and the stomach with volvulus had herniated into the thorax through the defect. The hernia was considered to be iatrogenic. The diaphragmatic defect was large, and the diaphragm was thinning. We closed the defect by mesh repair. Laparoscopic mesh repair of the diaphragmatic hernia could be performed safely and with minimal invasiveness.     

Giant cell tumor of the rib

We experienced a rare case of giant cell tumor (GCT) arising in the 5^th rib involving the 5^th vertebral body and transverse process. A 57-year-old man presented with a well-defined mass in the left thoracic cavity on chest x ray examination. Chest computed tomography showed a heterogeneous 7cm-diameter mass originating in the posterior segment of the left 5^th rib. The tumor had spread to the 5^th thoracic vertebra destroying the left half of the body and transverse process. Magnetic resonance imaging showed a heterogeneous-intensity mass involving the 4^th to 6^th ribs. A radical excision of the tumor followed by a 50 Gy radiotherapy was performed after embolization of the feeding arteries. The pathological diagnosis was a GCT. The patient remains well without evidence of recurrence for 6 years following surgery. The present case is only the 14^th case of GCT arising in the rib to have been reported in Japan.     

A case of acute hepatitis E associated with multidrug hypersensitivity and cytomegalovirus reactivation

A 65-year-old Japanese man was hospitalized because of acute hepatitis and severe cholestasis due to hepatitis E virus (HEV) infection combined with a drug reaction to a cold preparation. He died of disseminated intravascular coagulation and severe intestinal bleeding due to systemic cytomegalovirus reactivation following the development of severe eruptions with marked eosinophilia due to drug hypersensitivity to taurine and ursodeoxycholate preparations. The close interaction between viral infection or reactivation and drug hypersensitivity was considered as a pathophysiology in this case, which emphasizes the need for further study of the immunological mechanism of the interaction.     

A case of aspergilloma detected after surgery for pneumothorax.

We report a case of aspergilloma in an 80-year-old male patient who had no identifiable underlying disease before surgery for pneumothorax. He was hospitalized for left pneumothorax. A chest CT revealed a large bulla in the left lung apex with a nodule (diameter; 1.5 cm) at the edge of the bulla. After thoracodocesis, air leakage persisted and a large bulla and nodule were resected. Aspergillus was detected histopathologically in the nodule. Treatment with itraconazole 200 mg a day followed, and 4 months later he had no recurrent pneumothorax or Aspergillus infection.     

Direct effect of cadmium on citrate uptake by isolated rat renal brush border membrane vesicles

High incidence of multiple kidney stone formation has been observed among workers exposed to cadmium (Cd). Citrate is known to be a protective factor against renal stone formation. To study the direct effect of cadmium on citrate uptake by the renal brush border membrane, we exposed isolated rat renal brush border membrane vesicles (BBMV) to cadmium and determined their citrate uptake characteristics. BBMV were prepared by the divalent cation precipitation method. Citrate uptake was measured by the Millipore rapid membrane filtration technique. Preincubation of BBMV with 2 and 10 mM CdCl₂ for 1 min significantly inhibited citrate uptake compared with that of BBMV without Cd. Analysis of the time course of citrate uptake during 30-min preincubation of BBMV with 0.5 mM Cd also revealed significant reduction of the uptake compared with that of the control BBMV without preincubation. These findings indicate that preincubation of BBMV with cadmium results in time-dependent and concentration-dependent inhibition of citrate uptake.     

Anti-cholinergic effect of verapamil on the muscarinic acetylcholine receptor-gated K+ channel in isolated guinea-pig atrial myocytes

Summary Effects of verapamil on the acetylcholine (ACh)-induced K⁺ current were examined in single atrial cells, using the tight-seal whole-cell clamp technique. The pipette solution contained guanosine-5-triphosphate (GTP) or guanosine-5-O-(3-thiotriphosphate) (GTP-S, a non-hydrolysable GTP analogue). In GTP-loaded cells, ACh induced a specific K⁺ current, which is known to be mediated by pertussis toxin-sensitive GTP-binding (G) proteins. Verapamil (0.1–100 M) depressed the ACh-induced K⁺ current in a concentration-dependent fashion. In GTP-S-loaded cells, the K⁺ current remained persistently after wash-out of ACh, probably due to irreversible activation of G proteins by GTP-S. Verapamil (0.1–100 M) also depressed the intracellular GTP-S-induced K⁺ current. However, the magnitude of verapamil-depression of the K⁺ current in GTP-S-loaded cells was significantly smaller than that in GTP-loaded cells at concentrations between 1 and 10 M of the drug. From these results, it is suggested that verapamil may block not only the function of muscarinic ACh receptors but also of G proteins and/or the K⁺ channel itself and thereby depress the ACh-induced K⁺ current in isolated atrial myocytes.Supported by grants from the Ministry of Education, Science and Culture of Japan and the Research Program on Ca Signal Control Send offprint requests to Y. Kurachi at the above address     

A possible role of midbrain dopamine neurons in short- and long-term adaptation of saccades to position-reward mapping

Dopamine (DA) neurons respond to sensory stimuli that predict reward. To understand how DA neurons acquire such ability, we trained monkeys on a one-direction-rewarded version of memory-guided saccade task (1DR) only when we recorded from single DA neurons. In 1DR, position-reward mapping was changed across blocks of trials. In the early stage of training of 1DR, DA neurons responded to reward delivery; in the later stages, they responded predominantly to the visual cue that predicted reward or no reward (reward predictor) differentially. We found that such a shift of activity from reward to reward predictor also occurred within a block of trials after position-reward mapping was altered. A main effect of long-term training was to accelerate the within-block reward-to-predictor shift of DA neuronal responses. The within-block shift appeared first in the intermediate stage, but was slow, and DA neurons often responded to the cue that indicated reward in the preceding block. In the advanced stage, the reward-to-predictor shift occurred quickly such that the DA neurons' responses to visual cues faithfully matched the current position-reward mapping. Changes in the DA neuronal responses co-varied with the reward-predictive differentiation of saccade latency both in short-term (within-block) and long-term adaptation. DA neurons' response to the fixation point also underwent long-term changes until it occurred predominantly in the first trial within a block. This might trigger a switch between the learned sets. These results suggest that midbrain DA neurons play an essential role in adapting oculomotor behavior to frequent switches in position-reward mapping.     

IDO expression on decidual and peripheral blood dendritic cells and monocytes/macrophages after treatment with CTLA-4 or interferon-gamma increase in normal pregnancy but decrease in spontaneous abortion

Recent data demonstrated that CD4+CD25+ regulatory T (Treg) cells and an enzyme called indoleamine 2,3-dioxygenase (IDO) mediate maternal tolerance to the fetus. Interestingly, Treg cells express the CTLA-4 molecule on their surface, and B7 (CD80/86) ligation by CTLA-4 enhanced IDO activity of dendritic cells (DCs) and monocytes by the induction of interferon gamma (IFN-gamma) production. In this study, we studied the IDO expression on peripheral blood monocytes and decidual monocytes or DCs after treatment with CTLA-4/Fc fusion protein or IFN-gamma using flow cytometry. IDO expressions on both peripheral blood DC and decidual DC and monocytes were up-regulated during normal pregnancy. On the other hand, both IDO expression on DC and monocytes after IFN-gamma treatment or CTLA-4 treatment were decreased in spontaneous abortion cases. The expression of CD86 on peripheral blood and decidual monocytes and DC in spontaneous abortion cases was lower compared with those in normal pregnancy subjects. Also, IFN-gamma production by decidual and peripheral blood mononuclear cells after CTLA-4/Fc treatment in spontaneous abortion cases was significantly lower than those in normal pregnancy subjects. These data suggest that CTLA-4 on Treg cells up-regulates IDO expression on decidual and peripheral blood DC and monocytes by the induction of IFN-gamma production.