Concomitant use of enteral nutrition therapy is associated with sustained response to infliximab in patients with Crohn's disease.

BACKGROUND/OBJECTIVES: A significant proportion of Crohn's disease (CD) patients receiving infliximab (IFX) maintenance therapy show loss of responsiveness despite a good initial response. The factors other than immunomodulators that prevent IFX dose escalation have yet to be fully elucidated. This study was performed to identify clinical factors or concomitant therapies associated with sustained response to IFX. SUBJECTS/METHODS: Seventy-four consecutive CD patients who had successful IFX induction therapy between 2002 and 2010 underwent IFX maintenance therapy. Patients showing loss of response to IFX were treated with IFX intensification therapy. Factors involved in the sustained response to IFX were investigated retrospectively. RESULTS: After a median follow-up of 85 weeks, loss of response to IFX was observed in 30 (40.5%) cases. On logistic regression analysis, concomitant use of enteral nutrition (EN) therapy (elemental and/or polymeric formulas) was identified as an independent factor associated with sustained response to IFX. Receiver operating characteristic curve analysis indicated a cutoff value of 600 kcal/day. We divided the patients into the 'EN group' (≥ 600 kcal/day) and 'control group' (<600 kcal/day). The cumulative number of loss of response was significantly lower in the EN group (odds ratio: 0.23, P = 0.0043). Kaplan-Meier analysis confirmed the significantly lower rate of loss of response in the EN group (P = 0.013). Multivariate hazard ratio was 0.37 (P = 0.025). Type of EN formula did not affect the results. CONCLUSIONS: Concomitant use of EN ≥ 600 kcal/day is likely to yield a sustained response to IFX in CD patients.

Global analysis of nuclear receptor expression and dysregulation in human osteoarthritic articular cartilage: reduced LXR signaling contributes to catabolic metabolism typical of osteoarthritis.

OBJECTIVE: Compare the expression and regulation of nuclear receptors (NRs) in osteoarthritic and normal human articular cartilage. METHOD: The transcriptional levels of 48 NRs and additional related proteins were measured in mRNA from human articular cartilage from subjects with osteoarthritis (OA) and compared to samples from subjects without OA, using microarrays, individual quantitative reverse transcriptase polymerase chain reaction assays, and a custom human NR TaqMan Low Density Array (TLDA). The functional effect of liver X receptor (LXR) activity in cartilage was studied by measuring proteoglycan (PG) synthesis and degradation in articular cartilage explant cultures following treatment with the synthetic LXR agonist T0901317. RESULTS: Thirty-one of 48 NRs analyzed by TLDA were found to be measurably expressed in human articular cartilage; 23 of these 31 NRs showed significantly altered expression in OA vs unaffected cartilage. Among these, LXRalpha and LXRbeta, and their heterodimeric partners retinoid X receptor (RXR)alpha and RXRbeta were all expressed at significantly lower levels in OA cartilage, as were LXR target genes ABCG1 and apolipoproteins D and E. Addition of LXR agonist to human OA articular chondrocytes and to cartilage explant cultures resulted in activation of LXR-mediated transcription and significant reduction of both basal and interleukin (IL)-1-mediated PG degradation. CONCLUSIONS: Articular cartilage expresses a substantial number of NRs, and a large proportion of the expressed NRs are dysregulated in OA. In particular, LXR signaling in OA articular cartilage is impaired, and stimulation of LXR transcriptional activity can counteract the catabolic effects of IL-1. We conclude that LXR agonism may be a possible therapeutic option for OA.

Effects of nutritional supplementation with antioxidant vitamins and minerals and fish oil on antioxidant status and psychosocial stress in smokers: an open trial.

Nutritional supplement foods containing antioxidant vitamins and minerals and fish oil (mainly docosahexaenoic acid, DHA, C22:6n-3), referred to as capsules, were administered to seven smokers every day for 34 days. Concentrations of antioxidant vitamins and minerals in serum, activity of superoxide dismutase in plasma and the concentration of 8-isoprostane (8-epi-prostaglandin F(2) alpha) in the urine showed an increase or a tendency to increase after the end of administration. The frequency of subjects showing poor state of psychological health evidenced by a total score of 8 points or more on the General Health Questionnaire (30-item edition) scale was 42.9%, although there was a significant decrease to 14.3% upon completion of administration of the capsules. These biochemical and psychological changes were mostly returned to the basal level one month after the end of administration of the capsules. The results suggest that administration of antioxidant vitamins and minerals and fish oil to smokers resulted in an increase in antioxidant capacity. Effectiveness in alleviating psychosocial stress likely to be attributable to DHA was also observed.

Treatment with sheng-mai-san reduces myocardial infarct size through activation of protein kinase C and opening of mitochondrial KATP channel.

Sheng-mei-san (SMS), a traditional Chinese formulation comprising Radix Ginseng, Radix Ophiopogonis and Fructus Schisandrae, has long been used for more than 700 years for patients with coronary heart disease. We attempted to clarify 1) whether SMS reduces myocardial infarct size, and 2) whether the infarct size-reducing effect of SMS is related to activation of protein kinase C and the opening of the mitochondrial KATP channels in Japanese white rabbits without collateral circulation. The results indicate that three days treatment but not acute treatment with SMS reduces myocardial infarct size through activation of protein kinase C and opening of the mitochondrial KATP channels.

N-methyl-1-deoxynojirimycin (MOR-14), an alpha-glucosidase inhibitor, markedly improves postischemic left ventricular dysfunction.

We examined whether pharmacological inhibition of glycogenolysis by N-methyl-1-deoxynojirimycin (MOR-14), a new compound which reduces the glycogenolytic rate by inhibiting the alpha-1,6-glucosidase activity of the glycogen-debranching enzyme, can protect the heart against postischemic left ventricular dysfunction. The hearts of male Sprague-Dawley rats were excised, and perfused on a Langendorff apparatus with Krebs-Henseleit solution with a gas mixture of 95% O2 and 5% CO2. The hearts were paced at 320 beats/min except during the ischemia. Left ventricular developed pressure (LVDP, mmHg), +/-dP/dt (mmHg/s), and coronary flow (ml/min) were continuously monitored. All hearts were perfused for a total of 120 min including a 30-min preischemic period followed by a 30-min episode of global ischemia and 60 min reperfusion. with or without 0.5 or 2 mM of MOR-14 during the 30-min preischemic period or the first 30 min of reperfusion. In another series of experiments, the myocardial content of glycogen and lactate was measured during the 30-min episode of ischemia in groups treated with and without 2mM of MOR-14. Preischemic but not postischemic treatment with MOR-14 significantly improved LVDP and +/-dP/dt without altering coronary flow during reperfusion in a dose-dependent manner. MOR-14 significantly preserved the glycogen content and significantly attenuated the lactate accumulation during the 30-min episode of ischemia. Preischemic treatment with MOR-14 is protective against postischemic left ventricular dysfunction through the inhibition of glycogenolysis in the isolated rat heart.

A novel anti-diabetic drug, miglitol, markedly reduces myocardial infarct size in rabbits.

1. We examined whether N-hydroxyethyl-1-deoxynojirimycin (miglitol), a new human anti-diabetic drug with effects to inhibit alpha-1, 6-glucosidase glycogen debranching enzyme and reduce the glycogenolytic rate as well as to inhibit alpha-1,4-glucosidase, could reduce infarct size in the rabbit heart. Rabbits were subjected to 30-min coronary occlusion followed by 48-h reperfusion. 2. The infarct size as a percentage of area at risk was not reduced by pre-ischaemic treatment with 1 mg kg(-1) miglitol (42.7+/-4.0%, n=10) compared with the saline control group (41.7+/-2.3%, n=10). However, it was significantly and dose-dependently reduced by pre-ischaemic treatment with 5 or 10 mg kg(-1) of miglitol (25.7+/-4. 5%, n=10, and 14.6+/-2.4%, n=10, respectively) without altering the blood pressure, heart rate or blood glucose level. However, there was no evidence of an infarct-size reducing effect after pre-reperfusion treatment with 10 mg kg(-1) of miglitol (35.0+/-3.0%, n=10). 3. Another 40 rabbits given 1, 5 and 10 mg kg(-1) of miglitol or saline before ischaemia (n=10 in each) were sacrificed at 30 min of ischaemia for biochemical analysis. Miglitol preserved significantly the glycogen content, and attenuated significantly the lactate accumulation in a dose dependent manner in the ischaemic region at 30 min of ischaemia. 4. Pre-ischaemic treatment, but not pre-reperfusion treatment, with miglitol markedly reduced the myocardial infarct size, independently of blood pressure and heart rate. A dose-dependent effect of miglitol on infarct size, glycogenolysis and lactate formation suggests that the mechanism may be related to the inhibition of glycogenolysis. Thus, miglitol may be beneficial for coronary heart disease as well as diabetes mellitus.

A novel activating mutation in calcium-sensing receptor gene associated with a family of autosomal dominant hypocalcemia.

Autosomal dominant hypocalcemia (ADH), caused by activating mutations of the calcium-sensing receptor (CaSR), is characterized by hypocalcemia with an inappropriately low concentration of PTH. Among 11 missense mutations of CaSR reported to date in patients with ADH or sporadic hypocalcemia, functional properties of 8 mutant CaSRs were characterized. Here, we describe a novel mutation of CaSR and its functional property in a family with ADH. The 41-yr-old male proband had asymptomatic hypocalcemia with a history of recurrent nephrolithiasis. His father had asymptomatic hypocalcemia, but his mother was normocalcemic. PCR-single strand conformation polymorphism and sequencing revealed that both the proband and the father had a novel heterozygous mutation in CaSR gene that causes lysine to asparagine substitution at codon 47 (K47N), which is in the extracellular domain of CaSR, like 6 of 11 known activating mutations. Using HEK293 cells transfected with wild-type or K47N CaSR complementary DNA, the intracellular Ca2+ concentration was assessed in response to changes in the extracellular Ca2+ concentration. The EC50 of the mutant CaSR for the extracellular Ca2+ concentration was 2.2 mmol/L and was significantly lower than that of wild-type (3.7 mmol/L). These results confirm that this mutation is responsible for ADH in this family. The fact that several inactivating mutations in familial hypocalciuric hypercalcemia occur in amino acid around K47 suggests the importance of the N-terminal portion of the receptor in extracellular Ca sensing.

Antithrombotic activity of avian crown dermatan sulfate.

The antithrombotic activity of dermatan sulfate from avian crown with the mean molecular weight of 38000 was compared to those from bovine intestine with the mean molecular weight of 16000 in vivo and in vitro. In an in vitro test, bovine intestine dermatan sulfate exhibited stronger effects on stimulation of heparin cofactor II and activation of Glu-plasminogen by tissue plasminogen activator. In vivo, avian crown dermatan sulfate more effectively prevented the development of thrombus in a rat deep vein thrombosis model. The measurement of plasma levels of these two kinds of dermatan sulfate revealed that avian crown dermatan sulfate circulated in higher concentration and longer duration than bovine intestine dermatan sulfate after intravenous administration to rats.

N-methyl-1-deoxynojirimycin (MOR-14), an alpha-glucosidase inhibitor, markedly reduced infarct size in rabbit hearts.

BACKGROUND: N-methyl-1-deoxynojirimycin (MOR-14), an alpha-glucosidase inhibitor, reduces the glycogenolytic rate by inhibiting the alpha-1,6-glucosidase of glycogen-debranching enzyme in the liver, in addition to possessing an antihyperglycemic action by blocking alpha-1,4-glucosidase in the intestine. Because the reduction of the glycogenolytic rate may be one of the mechanisms of myocardial protection in ischemic preconditioning, the compounds inhibiting myocardial alpha-1,6-glucosidase may be protective against ischemic damage. Thus, we investigated whether MOR-14 could inhibit alpha-1,6-glucosidase and reduce the infarct size in rabbit hearts without collateral circulation. METHODS AND RESULTS: MOR-14 dose-dependently decreased the alpha-1,6-glucosidase activity in rabbit heart extract. A tracer study demonstrated the myocardial uptake of a considerable amount of MOR-14 sufficient to fully inhibit alpha-1,6-glucosidase. To assess the infarct size-reducing effect of MOR-14, 54 rabbits were subjected to 30-minute coronary occlusion followed by 48-hour reperfusion. Preischemic treatment with 25, 50, and 100 mg/kg of MOR-14 dose-dependently reduced the infarct size (to 26+/-4%, 19+/-3%, and 14+/-2% of the area at risk, respectively), compared with the saline control (45+/-5%) without altering the blood pressure or heart rate. Another 40 rabbits given 100 mg of MOR-14 or saline 10 minutes before ischemia were euthanized at 10 or 30 minutes of ischemia for biochemical analysis. MOR-14 decreased the alpha-1,6-glucosidase activity to approximately 20% in vivo, reduced the glycogen breakdown, and attenuated the lactate accumulation at both 10 and 30 minutes of ischemia. CONCLUSIONS: Preischemic treatment with MOR-14 preserved glycogen, attenuated the accumulation of lactate, and reduced the myocardial infarct size by 69%. This cardioprotective effect was independent of changes of blood pressure and heart rate or regional blood flow. It may be associated with alpha-1,6-glucosidase inhibition, because MOR-14 markedly decreased the alpha-1,6-glucosidase activity in the heart.

Fluoride profiles in the cementum and root dentine of human permanent anterior teeth extracted from adult residents in a naturally fluoridated and a non-fluoridated area.

OBJECTIVES: To determine the effect of water fluoride concentration on the fluoride profile across the entire thickness of the cementum and root dentine of human permanent anterior teeth in adults. SUBJECTS: Twenty-eight human permanent anterior teeth from individuals aged from 30 to over 60 years were studied. SETTING: Teeth were obtained from a natural high-fluoride area (West Hartle-pool, UK; 1.0-1.3 ppm F in drinking water, WHP) and the other from a non-fluoridated naturally low fluoride area (Leeds, UK; 0.1 ppm F in drinking water, LDS). DESIGN: Cementum and root dentine were sampled using an abrasive micro-sampling technique from the cementum surface to the pulpal surface of root dentine. RESULTS: Fluoride concentration was higher in tooth roots (the cementum and dentine) taken from the naturally fluoridated area (WHP) than from the non-fluoridated area (LDS). Age and average fluoride concentration showed a positive correlation in WHP dentine, middle region of the root (r = 0.78, P < 0.001) and in the apical region of the root (r = 0.61, P < 0.05). WHP cementum had the strongest fluoride concentration correlation with age in the cervical region of the root (r = 0.67, P < 0.01). An analysis of variance (ANOVA) showed that the area (water fluoride content), age and number of years lived in the area combined with total age were significant. CONCLUSIONS: The fluoride content of cementum and root dentine in adult residents is related to fluoride content in drinking water.

Nicorandil reduces myocardial infarct size by opening the K(ATP) channel in rabbits.

UNLABELLED: We examined whether nicorandil reduces myocardial infarct size (1) when administered before ischemia, and (2) when administered before reperfusion, and whether (3) infarct size is influenced by the plasma nicorandil concentration and the opening of the K(ATP) channel. Anesthetized open-chest Japanese white male rabbits were subjected to a 30 min coronary occlusion (ischemia) and a 48 h reperfusion in the following six groups; Group 1 (n=9): control group, Group 2 (n=9): pre-ischemia to post-reperfusion group (nicorandil 10 microg/kg/min, i.v.), Group 3 (n=7): pre-ischemia to post-reperfusion+glibenclamide group (glibenclamide 0.3 microg/kg, i.v.+nicorandil 10 microg/kg/min, i.v.), Group 4 (n=8): pre-reperfusion to post-reperfusion group (nicorandil 10 microg/kg/min, i.v.), Group 5 (n=8): pre-ischemia low-dose group (nicorandil 10 microg/kg/min for 5 min i.v.), Group 6 (n=7): pre-ischemia high-dose group (nicorandil 100 microg/kg/min for 5 min i.v.). The plasma nicorandil concentrations were measured from blood samples taken immediately before the ischemia. After the 48 h reperfusion, the size of the infarct was measured histologically with immunohistochemical actin staining and expressed as a percentage of the area at risk. RESULTS: Infarct sizes were as follows; Group 1 (control): 41.0+/-3.5%, Group 2: 31.3+/-2.0% (P<0.05 vs. control), Group 3: 40.9+/-3.4%, Group 4: 45.2+/-4.4%, Group 5: 35.8+/-3.3%, Group 6: 25.2+/-3.9% (P<0.05 vs. control). Infarct size was inversely correlated with the plasma nicorandil concentrations (y=-0.031x+41.0, r=0.65, P<0.05). CONCLUSIONS: The pre-ischemic but not post-ischemic administration of nicorandil reduced the size of myocardial infarct by opening the K(ATP) channels, and this effect was dependent on the plasma nicorandil concentrations immediately before the ischemia induced in rabbits.

[Wernicke's encephalopathy developed several years after total gastrectomy. Report of 2 cases].

We present here 2 cases of Wernicke's encephalopathy developed several years after total gastrectomy. Case 1. A 48-year-old male developed impaired recent memory and unsteady gait. He had undergone total gastrectomy for advanced gastric cancer 5 years previously; he had been on tegafur regimen for 4 and a half years. He had had 630 ml of beer every day for 6 months until admission. On admission, there were bilateral abducens palsy, horizontal nystagmus, gait ataxia, and areflexia. Cranial MR imaging was unremarkable. After intravenous infusion of vitamin B1, the patient improved. Case 2. A 56-year-old male developed exertional dyspnea, memory loss, and unsteady gait. He had undergone total gastrectomy for a large submucosal tumor 4 years previously; he had had 300-500 ml of sake almost every day thereafter. Examination revealed bilateral abducens palsy, severe gait ataxia, and areflexia. Chest CT scans demonstrated moderate amount of pericardial effusion. Blood vitamin B1 level was abnormally low. After administration of vitamin B1, he improved. Both patients had had alcoholic drinks; laboratory findings demonstrated no liver dysfunction. Drinking alcohol, even in relatively small quantities, could precipitate the development of Wernicke's encephalopathy in gastrectomized individuals. Our 2 cases stress the importance of supplementary vitamin B1 administration after total gastrectomy.

Molecular cloning and functional expression of a cDNA for rat phospholipid hydroperoxide glutathione peroxidase: 3'-untranslated region of the gene is necessary for functional expression.

A full-length cDNA clone for phospholipid hydroperoxide glutathione peroxidase (PHGPx) was isolated from a rat brain. The cDNA was 0.761 kb in length and encoded 170 amino acids, which included a TGA-encoded selenocysteine at residue 46. The protein has a calculated molecular mass of 19,473 Da. We succeeded in the transient functional expression of a full-length cDNA for PHGPx, which includes the 3'-UTR, in COS-7 cells at the first attempt. Deletion of the 3'-UTR prevented the expression of the PHGPx activity and the incorporation of [75Se]selenious acid into the monomeric 19.7 kDa PHGPx protein. Thus, the 3'-UTR of the cDNA for PHGPx was required for the functional expression of PHGPx. Northern blot analysis demonstrated that the mRNA for PHGPx was widely expressed in normal rat tissues, especially in the testis. The mRNA levels of PHGPx in the cultured cells such as hepatomas, neuronal cells, nephroblastoma, and mammary myo-epithelial cells were higher than those of the tissues. The ratio of PHGPx to cytosolic glutathione peroxidase (cGPx) was significantly high in the testis and relatively high in the cultured cells. The mRNA levels of PHGPx in tissues were lower than those of cGPx.

Paramedian thalamic infarction following blunt head injury--case report.

A 19-year-old male was admitted following a blow to the face. Computed tomographic (CT) scans 1 hour after injury revealed low-density areas in the bilateral thalami and midbrain, which were enhanced postcontrast except for the core 3 hours later. CT scans 2 days after injury revealed that the size of the low-density areas had increased. CT scans and magnetic resonance images 3 weeks after injury disclosed only small infarcted lesions in the bilateral thalami, the right side of the midbrain, and the left internal capsule. These findings suggest that the injury initially caused thrombus on the basilar arterial wall, leading to occlusion of the perforators, but almost all affected perforators were recanalized. Bilateral thalamic infarction resulting from head injury is unusual, as is the transient nature of the infarction in this case.

Synovial fluid ferritin in traumatic hemarthrosis, rheumatoid arthritis and osteoarthritis.

Synovial fluid ferritin levels in patients with traumatic hemarthrosis (HA), rheumatoid arthritis (RA), and osteoarthritis (OA) were measured by double antibody radioimmunoassay. Synovial fluid ferritin levels were significantly higher in 60 patients with HA (mean +/- S.D., 536 +/- 536 ng/ml) and 39 patients with RA (614 +/- 486 ng/ml) than in 20 patients with OA (130 +/- 119 ng/ml) (p < 0.01). Individual levels, however, considerably varied. In HA patients, the synovial fluid ferritin level correlated well with the duration of hemarthrosis, but not with hemoglobin, hematocrit, or an inflammatory synovial fluid index such as the leukocyte count. In RA patients, there was no significant correlation between the synovial fluid ferritin levels and any inflammatory parameter, such as catalase activity, synovial leukocyte counts (including polymorphs and monocytes) or the duration of arthritis. Our results indicate that the synovial fluid ferritin level reflects primarily hemoglobin degradation and appears unrelated to inflammation in joint diseases.

Evaluation of selected plants for their toxic effects in canaries.

Leaves or fruit from 14 plants considered to be toxic to pet birds were administered by gavage to 15 pairs of canaries (Serinus canaria). Each bird was given 0.12 to 0.70 g of plant material. One pair served as a control and was given distilled water. The plant materials were flash-frozen in liquid nitrogen, pulverized, and resuspended in deionized water for administration. Of the plants tested, 5 (oleander, lupine, foxglove, yew leaves, and dieffenbachia) were considered highly toxic and were associated with acute death of birds. The remaining plant samples caused no, or only transient, clinical illness.

[Multicenter clinical evaluation of red cell concentrates stored up to 6 weeks in MAP, a new additive solution].

The clinical safety and efficacy of transfusion of red cell concentrates stored in MAP solution (MAP-CRC) containing mannitol, adenine, glucose, phosphate and citrate, into 39 anemic patients were evaluated. In 23 patients, infusion of MAP-CRC was alternated with infusion of ordinary CRC as a control. The MAP-CRC and CRC used in this study were stored at 4 degrees C for an average of 38.2 +/- 2.6 days (n = 52) and 18.1 +/- 2.2 days (n = 26), respectively. Red cell recovery was 77.5% for MAP-CRC and 82.5% for CRC, based on calculation of the increase in hemoglobin level one day after transfusion. There were no differences between patients transfused with MAP-CRC and those transfused with CRC in clinical findings or biochemical data. No major side-effects other than pyrexia associated with the underlying infections were seen in patients transfused with MAP-CRC. MAP-CRC stored up to 42 days is apparently as safe and effective as stored CRC. This new additive solution may therefore be useful for the future expansion of the indications for autologous blood transfusion by facilitating the collection and storage of more blood in the liquid state for a longer period, and may also be useful in obtaining more plasma from whole blood as source plasma.

Improvement of postoperative hypocalcemia by repeated allotransplantation of parathyroid tissue without anti-rejection therapy.

Long lasting postoperative hypocalcemia, an uncomfortable complication of a thyroid operation for hyperthyroidism, was treated with allotransplantation of parathyroid tissue. Small pieces of the parathyroid tissue offered from two unrelated donors were transplanted to an 18-year-old male with severe postoperative hypoparathyroidism. Prednisolone was given for 2 days, but no other immunosuppressive drugs were used. The remaining tissue was stored in frozen for the repeat transplantation. The functional activity of the frozen tissue was determined by the production of parathyroid hormone in the tissue culture medium adjusted to appropriate concentration of calcium. Loss of the graft function, probably due to rejection, was supplemented with repeated grafting. Hypocalcemia was improved by three times of transplantation using frozen tissue (once) and fresh tissue (twice). This preliminary trial demonstrates that the tissue transplantation of the parathyroid gland is effective to lessen the symptoms and medication of postoperative hypoparathyroidism.

Immunohistochemical localization of calretinin in the rat hindbrain.

The localization of calretinin in the rat hindbrain was examined immunohistochemically with antiserum against calretinin purified from the guinea pig brain. Calretinin immunoreactivity was found within neuronal elements. The distribution of calretinin-immunoreactive cell bodies and fibers is presented in schematic drawings and summarized in a table. Major calretinin-immunoreactive neurons were found in the lateral and medial geniculate nuclei, substantia nigra, ventral tegmental area, interpeduncular nucleus, periaqueductal gray, mesencephalic trigeminal nucleus, superior and inferior colliculi, pontine nuclei, parabrachial nucleus, dorsal and laterodorsal tegmental nuclei, cochlear nuclei, vestibular nuclei, medullary reticular nuclei, nucleus of the solitary tract, area postrema, substantia gelatinosa of the spinal trigeminal nucleus, and cerebellum. These results show that distinct calretinin-immunoreactive neurons are widely distributed in the rat hindbrain.