Aging effect on neutral amino acid transport at the blood-brain barrier measured with L-[2-18F]-fluorophenylalanine and PET

Neutral amino acids (NAAs) are transported from the blood to the brain using the same carrier system in a competitive fashion. The purpose of this study is to establish a method for evaluating neutral amino acid transport at the blood-brain barrier (BBB) in humans and to examine the aging effect of amino acid transport.

METHODS

A dynamic PET study with L-(2-18F)-fluorophenylalanine (18F-Phe) was performed in 14 normal volunteers (age 21-71 yr; mean +/- s.d., age range 48.0 +/- 17.1 yr). By using a two-compartment model analysis and a weighted integration technique, the influx rate constant K1, the efflux rate constant k2 and distribution volume Vd of 18F-Phe were estimated in various brain structures.

RESULTS

The value of K1 was inversely correlated with plasma NAA concentration (r = -0.69, p < 0.01). The cerebellum showed the highest value of K1, while the white matter showed the lowest. There was no significant change in K1 during aging. The value of k2 was significantly increased with age.

CONCLUSION

No decline of K1 during aging indicated that NAA transport from the blood to the brain is a limiting process of age in amino acid incorporation. Fluorine-18-Phe PET imaging is a feasible method to study NAA transport at the BBB in vivo in humans and can be applied to pathological conditions of the brain.

Anatomical configuration of the spinal column in the supine position. II. Comparison of pregnant and non-pregnant women

To assess the changes in the curvature of the spinal column in the supine position during pregnancy, we studied seven pregnant (32-37 weeks of pregnancy) and seven non-pregnant women using magnetic resonance imaging. T1-weighted sagittal midline magnetic resonance images of the spinal column were obtained with subjects in the supine position with left tilt. There was no significant difference in the maximum angle of decline of the lumbar spinal canal between the pregnant (mean 12.4 (SD 3.3) degrees) and non-pregnant (13.4 (3.9) degrees) groups. The maximum angle of incline of the upper thoracic spinal canal was smaller in the pregnant (15.8 (2.9) degrees) than in the non-pregnant (22.7 (6.0) degrees) group. The highest point of the lumbar spinal canal was located at a lower lumbar region in the pregnant (median L4-5 (range L4 to L4-5)) than in the non-pregnant (L4 (L3-4 to L4)) group. The lowest point of the thoracic spinal canal was located at a higher thoracic region in the pregnant (T6-7 (T6 to T7-8)) than in the non-pregnant (T8 (T6-7 to T9)) group. This study revealed that the apex of lumbar lordosis was caudad and thoracic kyphosis was reduced in the supine position in the later stages of pregnancy. These changes in the curvature of the spinal column may explain, in part, the enhanced cephalad spread of subarachnoid hyperbaric anaesthetic solutions in the later stages of pregnancy.

Stimulation of glossopharyngeal and laryngeal nerve afferents induces expulsion only when it is applied during retching in paralyzed decerebrate dogs

Stimulation of the oropharyngeal mucosa induces vomiting in humans, however, it has not been seen in animals. Thus, we attempted to induce fictive vomiting by stimulation of lingual and pharyngeal branch afferents of the glossopharyngeal nerve, and afferents of the superior and recurrent laryngeal nerves in paralyzed decerebrate dogs. The stimulation did not induce fictive vomiting when it was applied during eupnea, but induced fictive expulsion when it was applied during fictive retching. Threshold intensity for the induction decreased with the progress of retching.

Dissecting thoracic aorta and fusiform aneurysm of the abdominal aorta

A 59-year-old woman with dissection of the thoracic aorta and a fusiform aneurysm of the abdominal aorta without evidence of Marfan's syndrome underwent aneurysmorrhaphy with a bifurcated expanded polytetrafluoroethylene graft. Histological specimens of the aneurysmal wall revealed the presence of idiopathic cystic medial necrosis. As typical findings of idiopathic cystic medial necrosis in the aortic wall are very rare except in cases of Marfan's syndrome, the present case is reported and the implications of this condition are discussed.

[Effect of horizontal lithotomy position on spread of hyperbaric dibucaine spinal anesthesia]

We have studied the effect of horizontal lithotomy position on the spread of hyperbaric dibucaine spinal anesthesia. In three groups of 20 patients, 7.2 mg of hyperbaric dibucaine was injected intrathecally in the lateral decubitus position. In group supine, the patients were kept in supine horizontal position in which patient's legs and thighs were extended throughout the operation. In group lithotomy A, immediately after the spinal injection, the patients were placed into the lithotomy position. In group lithotomy B, after the spinal injection, the patients were placed immediately in the supine horizontal position for 15 min and then placed into the lithotomy position. There were no significant differences in height of sensory blockade among the three groups. The lithotomy position did not significantly affect the level of sensory blockade with hyperbaric dibucaine.

[Continuous monitoring of arterial blood oxygen saturation with a pulse oximeter during spinal anesthesia]

The arterial oxygen saturation was continuously monitored in 50 patients under spinal anesthesia. Of the 50 patients, low oxygen saturation below 95% and/or its decrease of more than 5% was observed in 19 patients (38%). The remaining 31 patients (62%) showed a normal oxygen saturation. Pentazocine 0.5 mg.kg-1 i.v. correlated significantly with arterial oxygen desaturation (P = 0.0001). It is possible that laparotomy is associated with the desaturation (P = 0.0582). No correlation between desaturation and the other factors (level of analgesia, position during operation, and hydroxyzine premedication) was found.

Error analysis of table look-up method for cerebral blood flow measurement by 123I-IMP brain SPECT: comparison with conventional microsphere model method

While N-isopropyl-p-[123I]iodoamphetamine (IMP) is commonly used as a flow tracer, significant clearance from the brain causes underestimation of CBF as compared with true CBF when conventional microsphere model analysis is applied. We previously reported a simple "table look-up" method for CBF measurement using IMP taking into account this clearance effect. The method is based on a two-compartment model, the K1 (corresponding to CBF) and k2 constants being obtained from a table from the ratio of the 1st SPECT (40 min) to the 2nd SPECT (180 min) counts. Arterial input data used were obtained by one point blood sampling 10 min after IMP infusion against the standard input function. In the present study, this approach was compared with conventional microsphere model analysis. For 30 subjects, the latter method entailed 8 min continuous arterial blood sampling after IMP infusion and the use of SPECT data at the end of this period, calibrated by a count ratio of 8 min/40 min planar images of whole brains. A good correlation was observed between the two methods (r = 0.88), but an overestimation of table look-up method CBF as compared with microsphere model CBF was observed contrary to theoretical predictions. Limitations in the estimation of SPECT data at 8 min, obtained with SPECT data at 40 min for calibration of the count ratio of 8 min/40 min whole brain planar images, might be responsible for this.

[Rectal diclofenac coupled with continuous epidural infusion with buprenorphine and bupivacaine for pain relief after upper and lower abdominal surgery]

This investigation was conducted to determine the analgesic efficacy of rectal diclofenac coupled with continuous epidural infusion with buprenorphine and bupivacaine for pain relief after upper and lower abdominal surgery. Forty patients in control group received epidural buprenorphine 0.1 mg in 8 ml of 0.25% bupivacaine immediately after surgery and subsequently infusion was started with the solution of epidural buprenorphine 15 micrograms in 1 ml of 0.23% bupivacaine at a rate of 1 ml.h-1 for 48 h. Forty patients in study group received rectal diclofenac 50 mg immediately after surgery in addition to the same epidural injection method described above. Adding rectal diclofenac to continuous epidural infusion of buprenorphine and bupivacaine produced enhanced analgesia and reduced pain scores measured by VAS after upper abdominal surgery. However, after lower abdominal surgery, such effects of rectal diclofenac obtained after upper abdominal surgery were not demonstrable.

Therapeutic effect of percutaneous ethanol injection on small hepatocellular carcinoma: evaluation with CT

PURPOSE

To evaluate the therapeutic effect of percutaneous ethanol injection (PEI) on small hepatocellular carcinoma (HCC) with computed tomography (CT).

MATERIALS AND METHODS

Sixty-seven patients with histologically proved HCC 3 cm or less in diameter underwent PEI. The patients were regularly followed up with sonography and contrast material-enhanced CT for more than 1 year (range, 12-96 months). The CT findings were evaluated for three tumor types distinguished on the basis of their appearance relative to that of the surrounding liver parenchyma: type 1 = hyperattenuating at the early phase (n = 39), type 2 = iso- or hypoattenuating at the early phase and hypoattenuating at the late phase (n = 18), and type 3 = isoattenuating (not detected) at both the early and late phases (n = 10).

RESULTS

After PEI, a necrotic area of HCC and the surrounding liver parenchyma was characterized as hypoattenuating at both early and late phases of contrast-enhanced CT, regardless of the type. When an HCC appeared to be completely necrotic within 3 months after PEI, this status was retained until the latest observation in all but three cases.

CONCLUSION

Contrast-enhanced CT can correctly depict PEI-induced necrosis in HCC and is reliable for evaluating the therapeutic effect of PEI.

[Spinal anesthesia for oophorectomy in a patient with pulmonary lymphangiomyomatosis accompanied by hypochondriasis]

A 41-year-old woman with pulmonary lymphangiomyomatosis had been scheduled for bilateral oophorectomy which led to amelioration of the pulmonary pathology. The discrepancy between her dyspnea on exertion and lung function tests suggested that she had a marked tendency toward hypochondria. Therefore, we chose spinal anesthesia because of its technical simplicity, rapid onset, and effectiveness of some sedatives used perioperatively. Surgery was performed uneventfully. The anesthetic method mentioned above did not worsen respiratory function perioperatively. Spinal anesthesia is thought to be appropriate anesthesia for patients with pulmonary lymphangiomyomatosis, if feasible.

Polyunsaturated fatty acid-mediated suppression of insulin-dependent gene expression of lipogenic enzymes in rat liver

The effects of dietary polyunsaturated fat on insulin-dependent gene expression of lipogenic enzymes and a possible mechanism for PUFA-mediated suppression of the gene expression have been investigated in rat livers. When diabetic rats were injected with insulin, the insulin dose-dependent induction of lipogenic enzyme mRNAs were markedly reduced with increasing dietary corn oil. On the other hand, the PUFA-mediated suppression of the mRNA concentrations was partially restored by treatment with pioglitazone, a candidate for increasing insulin receptor phosphorylation. Moreover, insulin binding to receptors of liver, receptor autophosphorylation, and kinase activity toward exogenous substrate were lower in the corn oil diet group than in the hydrogenated fat group. The PUFA-mediated suppression of insulin binding was somewhat restored by pioglitazone, and the suppression of insulin receptor phosphorylation was significantly restored. It is suggested that the PUFA-mediated suppression of insulin-dependent gene expression of lipogenic enzymes can be ascribed to a decrease in insulin receptor binding primarily and also to receptor phosphorylation. Thus, PUFA appears to suppress the lipogenic enzyme gene expression stimulated by insulin.

Rapid calculation of regional cerebral blood flow and distribution volume using iodine-123-iodoamphetamine and dynamic SPECT

Iodine-123-iodoamphetamine (IMP) is commonly used as a flow tracer for SPECT due to its large first-pass extraction fraction. Significant clearance from the brain, however, causes changes in distribution and underestimation of CBF values when a conventional microsphere model is applied to prolonged data acquisition. We have developed a rapid method to calculate CBF images in which clearance effects are taken into account.

METHODS

A dynamic SPECT scan was obtained from five subjects (four patients with cerebral infarctions and one healthy volunteer) following intravenous injection of IMP lasting 1 min. The arterial input function was obtained by frequent blood sampling and measurement of the octanol extraction ratio. The dynamic images were weighted and integrated so that the look-up table procedures yielded values of CBF and distribution volume (Vd) simultaneously.

RESULTS

Calculated values for CBF and Vd were consistent with those determined by nonlinear least squares fitting [CBF: Y = 1.03X-0.30 (ml/100 ml/min), r = 0.998, p < 0.001; Vd: Y = 0.99X-0.11 (ml/ml), r = 0.99, p < 0.001] and calculated CBF correlated significantly with CBF measured by PET [Y = 0.85X-0.15 (ml/100 ml/min), r = 0.92, p < 0.001].

CONCLUSION

This technique is valid for estimating CBF.

[Postoperative analgesia service by continuous epidural infusion with buprenorphine]

We examined the analgesic efficacy and side effects of continuous epidural infusion with buprenorphine in 340 surgical patients. The patients received epidural injection of 0.1 mg of buprenorphine in 8 ml of 0.25% bupivacaine immediately after surgery. The patients who underwent thoracotomy or intraabdominal surgery were subsequently infused with buprenorphine 15 micrograms in 1 ml of 0.25% buprenorphine at a rate of 1 ml.h-1 for 48 h. In the other kinds of surgery, patients were infused with buprenorphine 8 micrograms in 1 ml of 0.25% buprenorphine at a rate of 1 ml.h-1 for 48 h. The patients who did not need additional narcotics were 68% and 83% on the postoperative day 1 and 2, respectively. Visual analogue scale (VAS) was 22 +/- 2 mm at rest and 43 +/- 2 mm at movement on the postoperative day 1. Corresponding values on the postoperative day 2 were 16 +/- 2 mm and 37 +/- 2 mm, respectively. Nausea and vomiting were found in 12.4% of the patients.

Spread of subarachnoid hyperbaric amethocaine in pregnant women

In order to examine how the gestational period influences the spread of spinal anaesthesia, we have measured the extent of spinal block produced by hyperbaric amethocaine 8 mg in 90 women. The patients were allocated to one of five groups according to the gestational period: non-pregnant group (n = 17), first trimester group (6-12 weeks, n = 14), second trimester group (13-24 weeks, n = 26), third trimester group (25-36 weeks, n = 15) and term group (37-41 weeks, n = 18). Maximum cephalad spread of analgesia was significantly higher in the second trimester (median T3 (range T9-C6)), third trimester (T3 (T4-C7)) and term groups (T2.5 (T4-C8)) than in the nonpregnant (T4 (T8-T2)) and first trimester groups (T4 (T11-C7)). We found that not only term pregnancy but also second and third trimester pregnancies enhanced the spread of spinal anaesthesia, and that first trimester pregnancy did not affect the spread of spinal anaesthesia.

The detection of the mRNAs of procollagen types I, II and III in human fetal fingers by in situ hybridization using digoxigenin-labelled oligonucleotide probes

Messenger RNAs (mRNAs) encoding procollagen alpha 1 type I,alpha 1 type II and alpha 1 type III have been localized in paraffin sections of human fetal fingers using digoxigenin-labelled synthetic oligonucleotide probes. The probe-mRNA hybrids were visualized using an anti-digoxin antibody amplified with sandwich techniques. These protocols provided an excellent hybridization signal with minimal background noise. The sensitivity of the protocols was nearly equivalent to that seen when using isotopic cDNA probes. In human fetal fingers, intense hybridization signals for procollagen alpha 1 type I mRNA were detected in the osteoblasts and the fibroblasts of periosteum and perichondrium, the tenocytes of tendons, fibroblasts of ligaments, the synovial membrane and deeper layers of the dermis. In contrast, positive hybridization signals for procollagen alpha 1 type II mRNA were visualized in chondrocytes and the cambial layer of perichondrium. The signals for procollagen alpha 1 type III mRNA were detected in the fibroblasts of the dermis and perichondrium. The probes which have lower melting temperatures (Tm) could not detect the corresponding mRNAs.

Isolation of a carrot gene expressed specifically during early-stage somatic embryogenesis

We report the first successful isolation by subtractive hybridization of a gene expressed specifically during somatic embryogenesis. Embryogenic cell clusters, 32-50 microns in diameter, were isolated by sieving and density-gradient centrifugation. The cDNA library was constructed from proglobulars which were formed from embryogenic cell clusters 3 days after transfer to auxin-free modified Lin and Staba's medium. For use as probe in screening, the same cDNA used for library construction was enriched for specific sequences using subtractive hybridization. The cDNA used for subtraction was prepared from suspension cultures 5 days after subculturing in auxin-containing medium. Nine independent differentially expressed cDNA clones were obtained from a screen of 150,000 recombinant phages. Northern analysis indicated one of these, CEM6, to be expressed specifically during somatic embryogenesis. In addition, one hybridizing transcript was detected in plantlet cotyledons, and two transcripts were detected in hypocotyls. Two separate and distinct hybridizing transcripts are expressed specifically in hypocotyl tissue. The amino acid sequence deduced from the nucleotide sequence of the CEM6 cDNA indicates that it encodes a glycine-rich protein containing a hydrophobic signal-sequence like domain. Its early embryo-specific expression and sequence characteristics suggest an important role as a cell wall protein in embryogenesis.

Cloning and characterization of polyphenol oxidase cDNAs of Phytolacca americana

Two cDNA clones encoding polyphenol oxidases were isolated from a cDNA library constructed from a log-phase suspension culture of Phytolacca americana (pokeweed) producing betalains. The clones exhibit 93 and 86% sequence identity at the nucleotide and deduced amino acid levels, respectively. Both clones contain two copper-binding domains characterized by histidine-rich regions, which are found ubiquitously in all polyphenol oxidases/tyrosinases, and a putative third histidine-rich, copper-binding region, which is common to all plant polyphenol oxidases. One of the Phytolacca cDNA deduced amino acid sequences contains the ubiquitous transit peptide for all proteins targeted to the internal lumen of thylakoid membranes of plastids and is considered to be 98 residues in length based on a proposed sequence cleavage site motif. This would produce a processed peptide of approximately 54 kD. In addition to common features of transit peptides, it was found that an additional conserved region for polyphenol oxidases was located between the hydroxy amino acid-rich region and the thylakoid transfer domain. Spatial and temporal expression was investigated by northern blot analysis of total RNA from various organs of Phytolacca plants. Transcripts of the two clones were found to be 2.1 and 2.3 kb, respectively. Both transcripts were present only at substantial levels in ripening, betalain-containing fruit.

[Continuous epidural buprenorphine for postoperative pain relief after thoracotomy]

To evaluate postoperative analgesia and side effects of epidural buprenorphine, 60 patients after thoracotomy were divided into 6 groups. All patients received a bolus epidural administration of buprenorphine 0.1 mg in 8 ml of 0.25% bupivacaine. Following this epidural bolus, 10 patients in each group were given 0.25% bupivacaine alone (group A), buprenorphine 5 micrograms in 1 ml of 0.25% bupivacaine (group B), buprenorphine 8 micrograms in 1 ml of 0.25% bupivacaine (group C), buprenorphine 12 micrograms in 1 ml of 0.25% bupivacaine (group D), buprenorphine 15 micrograms in 1 ml of 0.25% bupivacaine (group E) or buprenorphine 18 micrograms in 1 ml of 0.25% bupivacaine (group F) with a portable disposable device at a rate of 1 ml.h-1 for 48 h. The percentages of patients who did not need additional narcotics for the first 24 hours postoperatively in group A, B, C, D, E, and F were 20%, 40%, 30%, 50%, 60%, and 70%, respectively. Those for the second 24 hours postoperatively in each group were 40%, 50%, 70%, 60%, 90%, and 90%, respectively. No significant difference in the incidence of side-effect was found among 6 groups. We concluded that optimal epidural doses of buprenorphine for post-thoracotomy pain relief are 15 and 18 micrograms.h-1 in the first and second 24 hours postoperatively, respectively.

[Psychological evaluation of out-patients in our pain clinic using self-rating depression scale and state-trate anxiety inventory questionnaire]

In 98 out-patients who visited our pain clinic, we evaluated their psychological status before the first examination and one month after the treatment, using self-rating depression scale (SDS) and state-trate anxiety inventory (STAI). SDS, state anxiety, and trate anxiety scores were significantly higher in the patients with pain (trigeminal neuralgia, neck-shoulder-arm pain syndrome, lumbago and psychological pain, n = 55) compared with the patients without pain (sudden deafness and facial nerve palsy, n = 43) (P < 0.01, 0.05, 0.01). Of the patients with pain, patients with psychogenic pain showed the highest score in every test. The scores of SDS and state anxiety became significantly lower one month after the treatments compared with ones before the first examination (P < 0.01). It was considered that the decline in every score was due to the treatments in our pain clinic. In patients whose score of trate anxiety before the first examination was more than 50 points, the SDS and state anxiety showed high scores even one month after the treatments. This finding suggests that these patients need psychosomatic managements.

Polyunsaturated fatty acid regulation of lipogenic enzyme gene expression in liver of genetically obese rat

The polyunsaturated fatty acid regulation of lipogenic enzyme gene expression in genetically obese rats (Wistar fatty, non-insulin-dependent diabetes mellitus) has been investigated. The hepatic mRNA concentrations and activities of lipogenic enzymes in the fatty and lean rat were greatly increased by feeding a hydrogenated fat diet to fasted rats, and also reached similar maximum levels with similar time courses. By feeding a corn oil diet, however, the increases were markedly reduced in the lean rats, but were not significantly reduced in the fatty rats. Consequently, when the animals were fed corn oil, the mRNA concentrations and activities in the fatty rats were higher than those in the lean. Thus, it appeared that the higher gene expression in the fatty rats can be ascribed to the defects of polyunsaturated fatty acid suppression. On the other hand, insulin binding to receptors in the liver was reduced by the corn oil diet in the lean rats but was not reduced in the fatty rats (although the insulin binding level was lower in the Wistar fatty rats than in the lean). Changes in the insulin receptor autophosphorylation and kinase activity toward exogenous substrate were similar to the insulin binding. It is suggested that the polyunsaturated fatty acids may not suppress insulin binding activity to receptors in the livers of the fatty rats, probably due to down regulation by hyperinsulinemia. The defects of polyunsaturated fatty acid suppression of lipogenic enzyme gene expression may be one of the factors of obesity.

Enhancement of cyclic AMP accumulation mediated by 5-HT after chronic amitriptyline treatment in NG 108-15 cells

1. The effects of chronic in vitro administration of amitriptyline, a tricyclic antidepressant, on 5-hydroxytryptamine (5-HT) receptor-mediated adenylyl cyclase activity was studied in the neuroblastoma x glioma hybrid cell line, NG 108-15. 2. Treatment of NG 108-15 cells with 8 microM amitriptyline for 3 days increased forskolin-stimulated (0.1 microM) adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation. Addition of 5-HT (0.1-100 microM) increased forskolin-stimulated cyclic AMP accumulation in amitriptyline-treated cells in a concentration-dependent manner. However, 5-HT did not affect forskolin-stimulated cyclic AMP accumulation in untreated cells. 3. The 5-HT4 receptor agonist, 5-methoxytryptamine, significantly enhanced forskolin-stimulated cyclic AMP accumulation in amitriptyline-treated cells. In contrast, amitriptyline treatment failed to modify 8-hydroxy-2-(di-n-propylamine) tetralin-induced inhibition of forskolin-stimulated cyclic AMP accumulation. 4. Pretreatment of cells with pertussis toxin did not affect the 5-HT-induced enhancement of cyclic AMP accumulation. 5. The 5-HT-induced enhancement of cyclic AMP accumulation in amitriptyline-treated cells was attenuated by the 5-HT4 receptor antagonists, GR 113808 and ICS 205-930, with relatively low potency. However, spiperone, SCH 23390, and pindolol were completely ineffective against this 5-HT-induced enhancement. 6. Chronic treatment with amitriptyline did not modify the cyclic AMP production stimulated by prostaglandin E1 or cholera toxin. This treatment also had no effect on GTP gamma S-, NaF-, and Mn(2+)-stimulated cyclic AMP accumulation in isolated cell membranes. 7. Chronic treatment with the 5-HT receptor antagonists, pindolol or ICS 205-930, did not inhibit the 5-HT-induced enhancement of cyclic AMP accumulation.8. Chronic treatment with other antidepressant drugs, imipramine, mianserin or paroxetine, elicited the 5-HT-induced enhancement of cyclic AMP accumulation.9. Taken together, these results suggest that chronic amitriptyline treatment of NG 108-15 cells causes 5-HT to enhance forskolin-stimulated cyclic AMP accumulation by enhancing 5-HT receptor-mediated stimulation of adenylyl cyclase and not by reducing 5-HT-mediated inhibition of adenylyl cyclase. The 5-HT-induced enhancement of cyclic AMP accumulation in amitriptyline-treated cells may result from changes at the level of the 5-HT receptor rather than at the level of G, proteins or adenylyl cyclase. It is unlikely that this enhancement of cyclic AMP accumulation is caused by long-term antagonism of the 5-HT receptor by amitriptyline.

Demonstration of Mycoplasma hyorhinis as a possible primary pathogen for porcine otitis media

A study of the pathology of the ear was performed on 479 pigs ranging in age from 1 day to 1 year. Histologically, 364 (76.0%) of 479 pigs were affected with otitis. Eustachitis was the most common and preceded an inflammation of other sites of the ear, and an acute eustachitis occurred from as early as 1 week of life. Immunohistochemical examination of frozen cryostat sections revealed Mycoplasma hyorhinis (Mhr) antigens on the luminal surface of the eustachian epithelia in 14 (50.0%) of 28 piglets examined. All the pigs positive for Mhr had an acute eustachitis. Ultrastructural examination on the auditory tubes with positive immunostaining disclosed many mycoplasmas among the cilia. Mhr was isolated from the auditory tubes and tympanic cavities of 19 (67.9%) and 16 (57.1%) of 28 piglets examined, respectively. Porcine otitis media may be caused primarily by Mhr infection in the auditory tube.

Thyroid nodules: re-evaluation with ultrasound

The purpose of this study was to clarify ultrasound (US) evaluation of microcalcifications and determine whether the calcifications seen in US scans can reliably predict malignant thyroid tumors. Diagnostic accuracy of microcalcification and other various signs seen in US scans for predicting malignancy was evaluated prospectively in 259 pathologically verified thyroid nodules. Sonographic and pathologic correlation of calcifications was performed on 69 of 99 surgically removed nodules. Pathologic studies revealed that hyperechoic areas with acoustic shadowing represented mostly amorphous dense calcifications and sometimes microcalcifications, but small particles without acoustic shadowing mainly reflected microcalcifications and sometimes large amount of fibrous bands and condensed colloids. Of the various sonographic signs, microcalcification showed the highest accuracy (76%), specificity (93%), and positive predictive value (70%) for malignancy as a single sonographic sign, but its sensitivity (36%) was poor. Although sonographic microcalcification showed relatively high specificity, the accuracy of this finding for malignancy was insufficient.

Primary adenoid cystic carcinoma of the trachea: a case report of a twelve year survivor

Malignant tumors arising from trachea are not common. This paper presents an example of primary tracheal adenoid cystic carcinoma treated by surgical resection with good prognosis. A 46-year-old woman presented with a short history of dyspnea. Five months before the onset of dyspnea, the patient had mild wheezing. She had no history of smoking. Physical examination suggested primary tracheal tumor. The patient underwent a V-shaped resection of 3.5 cm of trachea followed by reconstruction with the trough method. Histological examination revealed adenoid cystic carcinoma. Adjuvant chemotherapy was indicated with 50 mg of adriamycin postoperatively. The patient has done well for 12 years with no further treatment. The tumor was an adenoid cystic carcinoma that was slow-growing, infiltration of mucus membrane was few and growth fraction (mitotic index was less than 1%) was low. Those were considered the reason for good prognosis.

TRH stimulation test in healthy elderly: paradoxical response of growth hormone is abnormal in normal aging

The purpose of this study was to measure TSH (thyrotropin), PRL (prolactin) and GH (growth hormone) response to a TRH (thyrotropin releasing hormone) stimulation test in 37 healthy elderly male subjects and determine if these responses correlate with the incidence of mental decline; and also, to determine if these responses occur more frequently in the elderly than in the general population. A hyperresponse of TSH was documented in 7 of our 37 elderly male subjects, a delayed response of TSH in 4, a low response of PRL in 29 and a significant paradoxical response of GH in 2. Those subjects with a significant paradoxical response of GH were 82 and 83 years of age and their HDS was 20.0 and 25.5, respectively. We did not find a causal relationship between mental decline and the paradoxical response of GH, but our data suggests that the paradoxical response of GH is not normal in elderly older than 80 years old.