Synapses are the site of connections between various nerve cells to interact, where neural information is processed through the mechanisms of synaptic transmission mediated by chemical messengers, including excitatory and inhibitory neurotransmitters. Whereas signals at excitatory synapses are mediated by the amino acid glutamate, inhibitory signals are mainly mediated by γ-aminobutyric acid (GABA). Exploring the mechanisms underlying the synaptic transmission and changes in its strength is, therefore, essential for our understanding of brain functions. The inhibitory synapse plays a critical role in controlling various functions of the brain. However, the mechanisms that regulate the strength of transmission at inhibitory synapses are poorly understood than those that regulate excitatory synapses. Therefore, I have been interested in the roles of neuromodulators on inhibitory GABAergic synapses in the cerebellum, whose basic neural circuits and synaptic mechanisms have been more thoroughly investigated than have those of other regions of the mammalian central nervous system. This knowledge base would allow results of experiments on cerebellar synapses to be interpreted more easily. Consequently, our studies have revealed that GABAergic synapses in the cerebellum are well modulated by different neuromodulators (monoamines and purines) liberated by different synaptic inputs converging on the same inhibitory synapses.
The confocal laser scanning microscope (CLSM) is a device for obtaining high-resolution optical images of immunofluorescent staining. The CLSM can produce in-focus images of thick specimens, a process known as optical sectioning. The images are reconstructed with a computer, using 3-dimensional image software, allowing 3-dimensional reconstructions of topologically complex objects. On the same tissue sections, the CLSM can obtain the images of differential interference contrast. Recently, a special inverted CLSM-the multimode microscopy system-has been used to examine the morphology and functions of cells. A multimode microscopy system can be used to obtain images of CLSM, total internal reflection fluorescence, time-lapse, and micromanipulation. In the present study, we show images of pancreatic cancer cells as an example.
An 80-year old man with a history of abdominal aortic aneurysm was emergently admitted to our hospital with suspected ileus. The previous day he had had back pain and abdominal pain. A chest X-ray film showed widening of the aortic shadow. A computed tomography scan with contrast enhancement revealed aortic dissection (Stanford B, De Bakey IIIb). We started conservative hypotensive therapy with nicardipine, without operation or stent grafting, because of the involvement of the major branches of the aortic arch. However, the false lumen was not thrombosed during conservative therapy. Three months later a computed tomography scan with contrast enhancement revealed aortic dissection with a false lumen from the left subclavian artery through the level of the diaphragm. Petechiae were noted over the skin of the thorax and abdomen. Coagulation studies revealed a low platelet count and increased levels of fibrin degradation products and thrombin-antithrombin, indicating disseminated intravascular coagulation due to chronic consumption coagulopathy associated with aortic dissection. Because the bleeding tendency persisted in spite of the initial hypotensive therapy and blood transfusion, we began antifibrinolytic therapy with tranexamic acid. After the antifibrinolytic therapy, the platelet count and levels of fibrinogen and fibrinogen degradation products improved, and the false lumen of the aortic dissection was thrombosed. We conclude that antifibrinolytic therapy with tranexamic acid is effective for treating disseminated intravascular coagulation and for thrombosing the false lumen of aortic dissection.
Synovitis due to atypical mycobacteriosis is often difficult to diagnose, because it presents with nonspecific clinical findings. We describe a case of wrist tendon sheath synovitis due to atypical mycobacteriosis, which was complicated by rheumatic arthritis. The patient was a 66-year-old woman with rheumatic arthritis. She was found to have synovitis on the palmar side of the right wrist in June 2006 and underwent synovectomy. Pathological examination of the synovial tissue extracted during surgery showed, only findings of rheumatic arthritis, and atypical mycobacteriosis was not diagnosed. Because swelling recurred after surgery, we performed synovectomy a second time. Culture for bacterial and, the tubercle bacillus and the polymerase chain reaction for atypical mycobacteriosis were all negative. Swelling recurred after the second synovectomy. Mycobacterium avium and, Mycobacterium intracellulare were identified in fluid obtained from puncture of the swollen wrist area, therefore, we started chemotherapy and performed synovectomy a third time. Swelling has not recurred in the year since the third synovectomy was performed. We believe that atypical mycobacteriosis should be considered when intractable wrist tendon sheath synovitis occurs.