Spirulina platensis and its ingredient biopterin glucoside improved insulin sensitivity in non-alcoholic steatohepatitis model.

Non-alcoholic steatohepatitis is the chronic liver disease leading to cirrhosis and cancer and its prevalence is increasing. Some agents are under clinical trials for non-alcoholic steatohepatitis treatment. We previously reported Spirulina (Arthrospira) platensis effectively prevented non-alcoholic steatohepatitis progression in our model rats. The contribution of phycocyanin, an ingredient of Spirulina (Arthrospira) platensis, was limited. We, therefore, have looked for more active components of Spirulina (Arthrospira) platensis. In this study, we pursued the effect of biopterin glucoside, another bioactive ingredient of Spirulina (Arthrospira) platensis. We found Spirulina (Arthrospira) platensis and biopterin glucoside oral administrations effectively alleviated oxidative stress, inflammation and insulin signal failure, and prevented fibroblast growth factor 21 gene overexpression in non-alcoholic steatohepatitis rat livers. We concluded biopterin glucoside is a major component of Spirulina (Arthrospira) platensis action.

Topological Regulation of the Bioactive Conformation of a Disulfide-Rich Peptide, Heat-Stable Enterotoxin.

Heat-stable enterotoxin (STa) produced by enterotoxigenic E. coli causes acute diarrhea and also can be used as a specific probe for colorectal cancer cells. STa contains three intra-molecular disulfide bonds (C1-C4, C2-C5, and C3-C6 connectivity). The chemical synthesis of STa provided not only the native type of STa but also a topological isomer that had the native disulfide pairings. Interestingly, the activity of the topological isomer was approximately 1/10-1/2 that of the native STa. To further investigate the bioactive conformation of this molecule and the regulation of disulfide-coupled folding during its chemical syntheses, we examined the folding mechanism of STa that occurs during its chemical synthesis. The folding intermediate of STa with two disulfide bonds (C1-C4 and C3-C6) and two Cys(Acm) residues, the precursor peptide, was treated with iodine to produce a third disulfide bond under several conditions. The topological isomer was predominantly produced under all conditions tested, along with trace amounts of the native type of STa. In addition, NMR measurements indicated that the topological isomer has a left-handed spiral structure similar to that of the precursor peptide, while the native type of STa had a right-handed spiral structure. These results indicate that the order of the regioselective formation of disulfide bonds is important for the regulation of the final conformation of disulfide-rich peptides in chemical synthesis.

A voxel-based analysis of brain activity in high-order trigeminal pathway in the rat induced by cortical spreading depression.

Cortical spreading depression (SD) is a self-propagating wave of depolarization that is thought to be an underling mechanism of migraine aura. Growing evidence demonstrates that cortical SD triggers neurogenic meningeal inflammation and contributes to migraine headaches via subsequent activation of trigeminal afferents. Although direct and indirect evidence shows that cortical SD activates the trigeminal ganglion (peripheral pathway) and the trigeminal nucleus caudalis (TNC, the first central site of the trigeminal nociceptive pathway), it is not yet known whether cortical SD activates the high-order trigeminal nociceptive pathway in the brain. To address this, we induced unilateral cortical SD in rats, and then examined brain activity using voxel-based statistical parametric mapping analysis of FDG-PET imaging. The results show that approximately 40h after the induction of unilateral cortical SD, regional brain activity significantly increased in several regions, including ipsilateral TNC, contralateral ventral posteromedial (VPM) and posterior thalamic nuclei (Po), the trigeminal barrel-field region of the primary somatosensory cortex (S1BF), and secondary somatosensory cortex (S2). These results suggest that cortical SD is a noxious stimulus that can activate the high-order trigeminal nociceptive pathway even after cortical SD has subsided, probably due to prolonged meningeal inflammation.

[Retropharyngo-esophageal hematoma treated by open paramedian tracheostomy].

Forty eight year-old woman with untreated liver cirrhosis was transferred to our critical care and emergency center because of airway crisis due to retropharyngo-esophageal hematoma after slight chest contusion. We performed emergency tracheal intubation beyond stenotic part of the trachea. The hematoma did not diminished in a few days. Although we considered tracheostomy, we hesitated to perform conventional median tracheostomy because of the risk of complication of infection of the hematoma which might require drainage or removal resulting in contamination between tracheostomy site and cervical wound. We performed paramedian tracheostomy by antero-lateral skin incision to avoid these risks. Fortunately, the patient did not require drainage of the retropharyngo-esophageal hematoma. Paramedian tracheostomy should be taken into account for patients with presumably contaminated cervical wound.

Outcomes from prehospital cardiac arrest in blunt trauma patients.

BACKGROUND: There are few strategies for treating patients who have suffered cardiopulmonary arrest due to blunt trauma (BT-CPA). The aim of this population-based case series observational study was to clarify the outcome of BT-CPA patients treated with a standardized strategy that included an emergency department thoracotomy (EDT) under an emergency medical service (EMS) system with a rapid transportation system. METHODS: The 477 BT-CPA registry data were augmented by a review of the detailed medical records in our emergency department (ED) and action reports in the prehospital EMS records. RESULTS: Of those, 76% were witnessed and 20% were CPA after leaving the scene. In all, 18% of the patients went to the intensive care unit (ICU), the transcatheter arterial embolization (TAE) room, or the operating room (OR). Only 3% survived to be discharged. Among the 363 witnessed patients-11 of whom had ventricular fibrillation (VF) as the initial rhythm, 134 exhibiting pulseless electrical activity (PEA), and 221 with asystole-13, 1, and 3%, respectively, survived to discharge. The most common initial rhythm just after collapse was not VF but PEA, and asystole increased over the 7 min after collapse. There were no differences in the interval between arrival at the hospital and the return of spontaneous circulation between the patients that survived to discharge and deceased patients in the ED, OR, TAE room, or ICU. The longest interval was 17 min. CONCLUSIONS: In BT-CPA patients, a 20-min resuscitation effort and termination of the effort are thought to be relevant. The initial rhythm is not a prognostic indicator. We believe that the decision on whether to undertake aggressive resuscitation efforts should be made on a case-by-case basis.

Usefulness and safety of open tracheostomy by a paramedian approach for cervical infection: esophageal and tracheal injury and necrotizing fascitis.

Tracheostomy is hardly performed in patients with cervical infection close to the site of the tracheostomy. This study aimed to present and clarify the usefulness and safety of open tracheostomy performed by the paramedian approach technique. The procedure is as follows. A 2.5-cm paramedian incision is made for the tracheostomy on the opposite side of infectious focus; the anterior neck muscles are dissected and split; the trachea is fenestrated by a reverse U-shaped incision; and the fenestral flap of the trachea is fixed to the skin. We used this technique in five patients. There were no complications such as bleeding, desaturation, and displacement of the tube; and there were no postoperative complications such as severe contamination or infection of the tracheostomy site from the nearby cervical wound, difficulty in securing the tracheostomy tube and connecting device to the ventilator, difficulties in daily management and care, or dislocation of the tracheostomy tube. All wounds resulting from the tracheostomy were kept separate from and not contaminated by the nearby dirty wounds. Open tracheostomy by the paramedian approach technique is useful and safe for patients with severe cervical infection requiring open drainage and long ventilatory management.

[Experience of damage control as the primary surgery for thoraco-abdominal injury with hemorrhagic shock].

We experienced a traumatic victim with thoracic and abdominal injury with hemorrhagic shock, who was successfully treated with damage control. Thoracic drainage revealed more than 300 ml/hour of continuous hemorrhage in the left thoracic cavity with 60-80 mmHg of non-responding hypotention. Although we performed emergency partial resection of the injured lung, intraabdominal packing and transcatheter arterial embolization, intrathoracic hemorrhage and hemorrhagic shock was not controlled. We decided re-thoracotomy and performed peri-pulmonary packing around the injured lung, by which we successfully controlled temporary intrathoracic hemorrhage and definitive left lower lobectomy. Peri-pulmonary packing was effective for intrathoracic hemostasis without lethal ventilatory and circulatory complication in this case.

Distribution of colour-selective activity in the monkey inferior temporal cortex revealed by functional magnetic resonance imaging.

Previous electrophysiological, neuroimaging and lesion studies have suggested that the anterior part of the monkey inferior temporal (IT) cortex, or area TE, plays an important role in colour processing. However, little is known about how colour information is distributed in these cortical regions. Here, we explored the distribution of colour-selective activity in alert macaque monkeys using functional magnetic resonance imaging (fMRI) with two types of stimuli: a multicoloured ('Mondrian') pattern and an isoluminant colour grating. These two types of stimuli are both commonly used in human fMRI studies, but Mondrian stimuli, which contain a richer variety of hues and hence might be more suitable for activating higher-order areas than grating stimuli, have not been used to examine colour-selectivity in higher-order areas in earlier monkey studies. With the Mondrian stimuli, we observed that areas along the ventral pathway, V1, V2/V3, V4 and the IT cortex, responded more strongly to colour stimuli than to luminance stimuli. In the IT cortex, we found that colour-selective activities are not distributed uniformly, but are localized in discrete regions, each extending several millimetres in the anterior or posterior part of the IT cortex. The colour-selective activation in the anterior IT was observed only with the Mondrian stimuli, whereas the colour-selective activation in the posterior IT was observed with both the Mondrian and grating stimuli, with little overlap. These findings suggest that there are multiple subregions with differing stimulus selectivities distributed in the IT cortex, and that colour information is processed in these discrete subregions.

Primary osteosarcoma of the breast.

Presented herein is a case of primary pure osteosarcoma of the breast. A 59-year-old woman noticed a left breast tumor. Mammography showed a cluster of crushed stone-like calcifications, which gave the tumor a raw cotton-like appearance. Malignancy was suspected on fine-needle aspiration cytology of the tumor. An excisional biopsy was performed. The tumor was 2.0 x 2.4 cm in size. Histopathologically the tumor was composed of diffuse atypical cells with mitosis and a lot of bone. Atypical cells were thought to be neoplastic osteoblasts. Multinucleated osteoclastic cells were interspersed with osteoblasts. Spindle cells were found at the verge of the tumor. A few entrapped tubular structures were seen. Immunohistochemistry indicated that neoplastic osteoblastic cells of the tumor were stained positively for vimentin, but negatively for epithelial markers; which suggested that the tumor cell elements originated from epithelial cells. This tumor was diagnosed as primary extraskeletal osteosarcoma. Partial resection was additionally performed around the excisional biopsy without dissection of the axillary lymph nodes. Bone radionuclide scan after operation showed no abnormal uptake. At 5 years after surgery no recurrence was seen.

Lethal obstructive colitis: how and when patients with colonic obstruction should be prevented from falling into a lethal condition.

BACKGROUND/AIMS: The objective of this study is to clarify the pathological condition and treatment strategy of lethal obstructive colitis (LOC), which is defined as obstructive colitis with severe shock or septic shock. METHODOLOGY: We examined 5 patients with LOC (colorectal cancer or suspected in 2, fecal impaction in 2, and volvulus in 1) and evaluated their pathophysiology and management strategy from their medical records. RESULTS: Emergency operations were performed within 150 minutes from arrival in all cases. Three were saved by repeat operations and 2 died. The systolic pressure of both survived and deceased patients were under 62 or palpable only on the common carotid artery, and there was no difference between survived and deceased patients. The mean pulse rate of the deceased patients was 76.5 while survived 117.7. Two deceased patients presented unconsciousness or conscious disorder while survived patients showed clear consciousness. The 2 deceased patients fell into VT just after arrival or during the operation. CONCLUSIONS: In managing colonic obstruction, we should be aware of this potentially lethal disease and surgical treatment should be performed as soon as possible before the patients fall into LOC. Early diagnosis and early aggressive surgery is essential for managing LOC.

Lethal perianal infection with septic shock: how should we manage this critical condition?

Some patients with perianal infection fall into a critical condition with severe sepsis and septic shock (lethal perianal infection). The objective of this study is to clarify the clinicopathological characteristics of, and treatment strategies for, lethal perianal infection. The clinical records of 7 patients with lethal perianal infection were examined. For two rapidly dying cases (within 3 days), we performed resection of the rectum or local anal drainage as a primary management of damage control. These patients were transferred to our center because of septic shock and multiple organ dysfunction syndrome (MODS) and had received insufficient fluid resuscitation in the previous hospital. Another nonsurviving case who died on the 16th day was transferred without MODS and underwent perianal drainage but could not recover from shock, even after repeated surgical procedures were performed. To prevent a perianal infection from becoming lethal, it should be managed as early as possible with sufficient fluid resuscitation with adequate drainage.

Functional segregation of the inferior frontal gyrus for syntactic processes: a functional magnetic-resonance imaging study.

We used functional magnetic resonance imaging in 18 normal volunteers to determine whether there is separate representation of syntactic, semantic, and verbal working memory processing in the left inferior frontal gyrus (GFi). We compared a sentence comprehension task with a short-term memory maintenance task to identify syntactic and semantic processing regions. To investigate the effects of syntactic and verbal working memory load while minimizing the differences in semantic processes, we used comprehension tasks with garden-path (GP) sentences, which require re-parsing, and non-garden-path (NGP) sentences. Compared with the short-term memory task, sentence comprehension activated the left GFi, including Brodmann areas (BAs) 44, 45, and 47, and the left superior temporal gyrus. In GP versus NGP sentences, there was greater activity in the left BAs 44, 45, and 46 extending to the left anterior insula, the pre-supplementary motor area, and the right cerebellum. In the left GFi, verbal working memory activity was located more dorsally (BA 44/45), semantic processing was located more ventrally (BA 47), and syntactic processing was located in between (BA 45). These findings indicate a close relationship between semantic and syntactic processes, and suggest that BA 45 might link verbal working memory and semantic processing via syntactic unification processes.

Trans-abdominal-mediastinal approach with median phrenotomy for esophageal disruption.

BACKGROUND/AIMS: The prognosis for esophageal disruption is still poor. The aim of this study is to clarify the usefulness and safety of the transabdominal-mediastinal approach for spontaneous esophageal disruption. METHODOLOGY: The surgical procedure is as follows: upper median laparotomy with resection of the xyphoid process, folding up of the lateral segment of the left liver, median phrenotomy from the root of the xyphoid process to the esophageal hiatus, trans-mediastinal left thoracotomy by blunt dissection, blind lavage of the thoracic cavity, and simple interrupted suture and fundic patch of this suture line, if necessary. RESULTS: We managed 3 cases using this technique. Two cases had severe prior chronic diseases (poorly controlled diabetes and liver cirrhosis, and hemodialysis). In all cases, the lesions were completely exposed in the abdomen by and the ruptured sites were safely and completely sutured under a good field of view. The left thoracic cavity was adequately washed. All cases were saved without lethal complication. One case showed minor leakage, which was easily managed by continuous high pressure aspiration using double luminal drainage system (CHPA-DLD). CONCLUSIONS: We concluded that our technique is useful for esophageal disruption long after the onset, with severe prior chronic diseases, or with pleuritis.

Monitoring and evaluation of intraperitoneal bleeding (IPB) by small portable ultrasonography during transcatheter arterial embolization (TAE) in abdominal-pelvic trauma patients with shock: as a monitor for early detection of increase of IPB.

BACKGROUND/AIMS: Blunt abdominal-pelvic trauma patients with shock often require transcatheter arterial embolization (TAE), and may also require surgery if intraperitoneal bleeding (IPB) becomes massive. Deciding whether the patient should undergo surgery is highly critical. We sometimes perform TAE without attention to IPB because it has been difficult to evaluate the volume of IPB exactly during TAE. Currently we use small portable ultrasonography (PUS) as a monitor of volume of IPB during TAE. The aim of this study is to clarify the usefulness of PUS for monitoring changes in IPB during TAE. METHODOLOGY: We examined the volume of IPB by PUS during TAE without disturbing the operators of TAE. In our protocol, if the volume of IPB showed rapid increase we tried to perform a surgical procedure. The design of this study was a prospective case series study. RESULTS: We examined 26 patients. Increase of IPB was detected in 3 cases; two were undergoing angiography for ileac and renal arteries when PUS indicated increase of IPB, which drew attention to their hepatic arteries. The other was examined initially for internal ileac artery and underwent surgery because of an increase of IPB. In the other 22 cases, we confirmed no increment of IPB by PUS and continued the procedure. CONCLUSIONS: PUS is useful for deciding the order of therapeutic procedure, and is a useful monitoring instrument for increase of IPB.

Gastrointestinal fiberscopic findings after simple closure for perforated duodenal ulcer in the early postoperative phase: from experience to evidence by evaluation of the healing process.

BACKGROUND/AIMS: Today, in light of widespread adoption of H2-RA and PPI, the standard surgical procedure for perforated duodenal ulcer (PDU) is simple closure and/or omental patch (SC). However, the healing process after these techniques has not been fully examined. We have not yet confirmed the propriety of simple suture of the bottom of the ulcer. This technique has been performed based only on experience, and there is insufficient evidence to conclude that this procedure can be definitively considered a safe therapeutic technique for the majority of patients with PDU. The aim of this study is to clarify the macroscopic findings of the healing process after SC for PDU. METHODOLOGY: Thirteen patients with PDU who were treated with SC underwent postoperative gastroduodenal fiberscopy (GF) at the 7th-16th postoperative day and the healing process was monitored under sufficient informed consent. Patients with severe preoperative disease were excluded from the study. Healing condition of the ulcer and stitches, deformity, and stenosis were evaluated by postoperative endoscopy. Possible adverse effects that were evaluated included: perforation, rise in fever, worsening of inflammation on laboratory data, gastrointestinal symptoms such as abdominal pain, sense of fullness, and vomiting. The indications for SC were as follows: PDU with 1) no stenosis and 2) no prominent ulcer ridge. The surgical technique was as follows: 1) interrupted simple closure with no trimming and debridement of wound (4-5 stitches) with absorbable monofilament suture, and/or 2) omental patch, 3) administration of H2-RA (or PPI) just after operation, and 4) oral feeding 4-5 days after operation independent of postoperative GF. RESULTS: GF findings in 2 patients showed active and healing stage, in whom surgical technique was thought to be insufficient; the ulcer had been large and included a descending portion, or a small perforation had occurred in the large ulcer bottom (the distance between the stitches and the edge of the ulcer was insufficient). In the other 11 patients, GF findings showed scar phase. There was no morbidity related to endoscopic procedure. CONCLUSIONS: Sutured PDU with SC will be in the scar phase in 1 or 2 weeks. Postoperative GF 1 week after SC for PDU is thought to be a safe examination. This study is a primitive study of a small group, and more cases that can adequately show the frequency of complications and indicate the overall safety of the procedure are needed.

Angiomyofibroblastoma of the vulva: a large pedunculated mass formation.

Angiomyofibroblastoma is a rare, usually small benign mesenchymal tumor that occurs in vulvar lesions of premenopausal women. A case of angiomyofibroblastoma that arose as a unique pedunculated and particularly large mass in the left vulva of a 48-year-old woman is presented herein. The patient had been aware of a gradually enlarged mass of 7 years duration without any other gynecological symptoms or signs. The maximum dimension of the tumor measured 11 cm. The resected tumor was well circumscribed with a bulging and glistening cut surface. Histological examination revealed an admixture of irregularly distributed hypercellular and hypocellular areas with spindled, plump spindled, or plasmacytoid stromal cells and abundant venular or capillary-sized vessels. Stromal cells characteristically cluster around delicate vessels within an edematous to collagenous matrix. In the present case, intralesional adipose tissue was present throughout the tumor. There was no significant nuclear atypia, and mitotic figures were very sparse. There was little stromal mucin throughout the tumor. Immunohistochemically, the stromal cells were characterized by strong reactivity for vimentin and CD34, with focal reactivity for desmin and alpha smooth muscle actin. Both estrogen and progesterone receptors were diffusely expressed in the stromal cells. These histological findings are consistent with angiomyofibroblastoma and support the hypothesis that angiomyofibroblastoma originates from perivascular stem cells with a capacity for myofibroblastic and fatty differentiation.

Relationship between vasodilatation and cerebral blood flow increase in impaired hemodynamics: a PET study with the acetazolamide test in cerebrovascular disease.

UNLABELLED: The changes in cerebral blood flow (CBF) and arterial-to-capillary blood volume (V(0)) induced by acetazolamide (ACZ) are expected to be parallel each other in the normal circulation; however, it has not been proven that the same changes in those parameters are observed in patients with cerebrovascular disease. To investigate the relationship between changes in CBF, vasodilatory capacity, and other hemodynamic parameters, the ACZ test was performed after an (15)O-gas PET study. METHODS: Twenty-two patients with unilateral major cerebral arterial occlusive disease underwent PET scans using the H(2)(15)O bolus method with the ACZ test after the (15)O-gas steady-state method. CBF and V(0) for each subject were calculated using the 3-weighted integral method as well as the nonlinear least-squares fitting method. After evaluation of accuracy in V(0) values, a new parameter, the CBF/V(0) ratio, which is expected to disclose arterial perfusion pressure, was also compared between the conditions. RESULTS: The regional CBF (rCBF) and V(0) increased significantly after ACZ administration in the hemisphere contralateral to the ischemic side. However, in a subgroup of patients who showed a significant reduction in the rCBF increase in the ipsilateral hemisphere (group A), the ACZ injection caused no change or a slight decrease in rCBF even though the V(0) showed a significant increase. Thus, the increases in rCBF and V(0) did not necessarily parallel each other in the ipsilateral hemispheres of patients who have impaired cerebral circulation. A parameter defined by the rCBF/V(0) ratio decreased significantly in the ipsilateral hemisphere of group A after ACZ administration, although the ratio showed no change in the contralateral hemisphere or in the other subgroup (group B). CONCLUSION: The change in the rCBF/V(0) ratio after ACZ challenge may represent an alteration in arterial perfusion pressure that is expected to indicate a critical hemodynamic status in patients with cerebrovascular disease, especially in patients who have a reduced rCBF response.

The effect of nitroglycerin on myocardial blood flow in various segments characterized by rest-redistribution thallium SPECT.

UNLABELLED: The use of nitrates is reported to be effective in viability detection in scintigraphic perfusion imaging. The purpose of the study was to evaluate the effect of nitroglycerin (NTG) on myocardial blood flow (MBF) and coronary vascular resistance (CVR) in various segments characterized by rest-redistribution (201)Tl SPECT. METHODS: Twenty-three patients with coronary artery disease underwent rest-redistribution (201)Tl SPECT and (15)O-labeled water PET at rest and after NTG spray (0.3 mg). In addition, 11 healthy volunteers were also studied using PET. RESULTS: NTG did not change global MBF in the volunteers or in the patients. In segments with normal (201)Tl uptake and in those with a severe irreversible (201)Tl defect, NTG significantly reduced MBF without changing CVR. NTG reduced CVR in segments with a reversible (201)Tl defect (141 +/- 50 to 114 +/- 29 mm Hg/[mL/min/g], P = 0.004) and in those with a mild-to-moderate irreversible (201)Tl defect (165 +/- 64 to 149 +/- 60 mm Hg/[mL/min/g], P = 0.003), while maintaining MBF. CONCLUSION: NTG preferentially reduces CVR in the viable myocardium with ischemia. After NTG, tracer uptake in the ischemic myocardium will be relatively increased compared with that in the nonviable and nonischemic myocardium, leading to improvements in viability detection.

Effect of caffeine intake on myocardial hyperemic flow induced by adenosine triphosphate and dipyridamole.

UNLABELLED: The aims of this study were (a). to compare absolute myocardial blood flow (MBF) during adenosine triphosphate (ATP) infusion with that after dipyridamole administration without caffeine intake and (b). to evaluate the effect of caffeine intake on the hyperemic flow induced by these coronary vasodilator agents. METHODS: MBF was quantified with (15)O-labeled water and PET at rest, during ATP infusion (0.16 mg/kg/min for 9 min), and after dipyridamole administration (0.56 mg/kg over 4 min) after a 24-h abstinence from caffeine (baseline evaluation) in 10 healthy volunteers. Within 2 wk, the same PET studies were repeated after caffeine intake to evaluate the effect of caffeine on the hyperemic flow induced by these pharmacologic agents (caffeine study). Myocardial flow reserve (MFR), defined as the ratio of hyperemic to resting blood flow, was also evaluated. RESULTS: Resting MBF in baseline and caffeine studies did not differ significantly (0.79 +/- 0.29 vs. 0.75 +/- 0.31 mL/min/g, P = 0.88). Without caffeine intake, MBF during ATP infusion was significantly higher than that after dipyridamole administration (3.70 +/- 0.67 vs. 3.00 +/- 0.79 mL/min/g, P = 0.003), whereas there was no significant difference in MFR between ATP and dipyridamole stress (5.15 +/- 1.64 vs. 4.11 +/- 1.44, P = 0.07). After caffeine intake, the hyperemic flows induced by ATP and dipyridamole were not significantly different (1.68 +/- 0.37 vs. 1.52 +/- 0.40 mL/min/g, P = 0.50). MFR estimated by ATP and dipyridamole also did not differ significantly in the caffeine studies (2.44 +/- 0.88 vs. 2.25 +/- 0.94, P = 0.73). MBF during ATP infusion and after dipyridamole administration were significantly lower in the caffeine studies than that in the baseline evaluation (1.68 +/- 0.37 vs. 3.70 +/- 0.67 mL/min/g, P < 0.0001, and 1.52 +/- 0.40 vs. 3.00 +/- 0.79 mL/min/g, P < 0.0001, respectively). CONCLUSION: This study demonstrates that ATP has the potential to induce greater hyperemia than dipyridamole, whereas hyperemic responses to ATP and dipyridamole are similarly attenuated after caffeine intake. These findings suggest that abstinence from caffeine before ATP stress testing may be needed.

Inner ear hearing loss modulates ipsilateral temporal lobe activation by monaural speech stimuli.

We examined cortical activation by speech in patients with moderate inner ear hearing loss using PET to investigate the response of the language network to insufficient speech input. We made two word lists, well-perceived words and poorly-perceived words, and measured rCBF during monaural presentation of these words. Well-perceived words activated bilateral temporal lobes, bilateral inferior frontal gyri (IFG) and left angular gyrus (AG) regardless of the ear stimulated, Poorly-perceived words activated contralateral temporal lobe and bilateral IFG, while little or no activation was observed in the ipsilateral temporal lobe and left AG. Insufficient activation of the temporal lobe ipsilateral to the ear stimulated might correlated with less accurate word comprehension in patients with inner ear hearing loss.