Human glial cell-line-derived neurotrophic factor: a structure-function analysis

Glial cell-line-derived neurotrophic factor (GDNF) is a protein known to enhance the survival of dopaminergic and motor neurons. It has been shown to have therapeutic potential in the treatment of Parkinson's disease and other neurodegenerative diseases. GDNF gene was modified by deletion and insertion mutagenesis using PCR methods. The various mutants were all highly expressed in Escherichia coli. The recombinant proteins were purified and their survival-promoting activities were determined by motor neurons. The result showed that the C-terminus was critical for structure stability of GDNF, and the alpha-helix, finger1 and finger2 regions were involved in receptor binding, while the N-terminus was not essential for the biological functions of GDNF.

Enhanced postprandial gastric myoelectrical activity after moderate-intensity exercise

OBJECTIVE

The aim of this study was to investigate the change of postprandial gastric myoelectrical activity and its relation with vagal activity after exercise.

METHODS

Nine subjects were studied in two sessions. In the control session, gastric myoelectrical activity was recorded using electrogastrography (EGG) for 30 min in the fasting state and 60 min after a test meal. In the exercise session, after the baseline recording of both the EGG and electrocardiogram (ECG), the subject was put on a cycle ergometer for exercise until reaching 50% of the maximum age-predicted heart rate for 10 min. The test meal was then given and the recording was resumed for 60 more minutes. Spectral analyses were performed on both the EGG and the heart rate variability derived from the ECG.

RESULTS

The postprandial increment of the dominant power (p<0.05) and the percentage of the 2-4 cpm slow waves (p = 0.01) were significantly higher with exercise. The standard deviation of the postprandial dominant frequency was significantly decreased (more stable slow waves) with exercise (p<0.04). While cardiac vagal activity was significantly decreased after the meal, exercise did not significantly affect the postprandial change.

CONCLUSIONS

Gastric slow waves become more regular, more stable, and of higher amplitude after exercise, and this enhancement is probably not mediated via the vagal pathway.

Interleukin-2: structural and biological relatedness to opioid peptides

Interleukin (IL)-2 is not only an immunoregulatory factor, but also an analgesic molecule. There are distinct domains of immune and analgesic functions in the IL-2 molecule. The analgesic domain is located around the 45th Tyr residue of human IL-2 in tertiary structure. Antiopioid (beta-endorphin, Leu-enkephalin, Met-enkephalin and dynorphin A1-13) sera partially neutralized the analgesic activity of IL-2. Monoclonal antibody against the IL-2 receptor alpha subunit (Tac) could not block the analgesic activity of IL-2. There existed cross-reactivity between IL-2 and antiopioid sera by indirect ELISA. These studies show strong structural and biological similarities between IL-2 and opioid peptides. The tertiary structure around the 45th residue of IL-2 composes the analgesic domain that is similar to that of endogenous opioids. These results are consistent with the hypothesis that multiple domains of cytokines serve as the structural bases for the immunoregulatory and neuroregulatory effects of cytokines.

Multiple functions of polypeptides mediated by distinct domains interacting with different receptors

There exist multiple functions of polypeptide molecules. Both a polypeptide molecule interacting with one receptor, and distinct domains of the molecule interacting with different receptors could induce different intracellular signal transduction to elicit multiple functions. This review highlights the distinct domains of the polypeptide molecule interacting with different receptors to elicit multiple functions. It includes distinct domains, different receptor mechanisms, and different signal transduction of the polypeptide molecule.

[Ciliary neurotrophic factor prevents NO mediated cytotoxicity in cultured hippocampal neurons]

The effects of ciliary neurotrophic factor on nitric oxide (NO)-induced cytotoxicity were examined in primary cultures of rat hippocampal neurons. The neurotoxicity was induced by NO donors, such as sodium nitroprusside (SNP), s-nitroso-N-acetylpenicillamine (SNAP), NOS substrate, L-arginine (L-Arg) and ionomycin (a calcium ionophore). Preincubation of the cultures with ciliary neurotrophic factor (CNTF) for 24 h promoted neuronal survival and decreased the LDH efflux and the level of NO induced by ionomycin. The protective effects of CNTF against NO cytotoxicity were concentration-dependent. The above findings suggest that CNTF promotes the survival of neurons in the hippocampus by preventing NO mediated neurotoxicity.

Microbiological response of localized sites with recurrent periodontitis in maintenance patients treated with tetracycline fibers

BACKGROUND

Whether adjunctive tetracycline fibers can provide an additive effect to scaling and root planing in treating non-responsive sites in maintenance subjects is still controversial. Recolonization of the bacteria from untreated sites or from the extracrevicular region may explain the insignificant response to local therapy. The purpose of the present study was to evaluate the microbiological response of sites treated with tetracycline fibers combined with scaling and root planing.

METHODS

The study was conducted in a split-mouth design. Thirty patients on maintenance therapy having at least 2 non-adjacent sites in separate quadrants with probing depths between 4 to 8 mm with bleeding on probing, or aspartate aminotransferase enzyme levels > 800 microIU in the gingival crevicular fluid, were treated with scaling and root planing plus tetracycline fibers or with scaling and root planing only. Subgingival plaque samples were collected at baseline, and 1, 3, and 6 months following treatment. A. actino-mycetemcomitans, C. rectus, B. forsythus, E. corrodens, F. nucleatum, P. gingivalis, and P. intermedia were detected by culture, immunofluorescence, or PCR technique.

RESULTS

There was a reduction of total bacterial cell count, as well as of certain periodontal pathogens, following treatment. The prevalence of A. actinomycetemcomitans, B. forsythus, and P. gingivalis and the mean proportions of C. rectus, P. intermedia, F. nucleatum, and P. gingivalis decreased after therapy, but there was no statistically significant difference between the 2 treatment groups with respect to bacterial proportions or the number of positive sites. Besides, the pathogens could not be eliminated from the periodontal pocket, and recolonization of the pocket was noted at 3 months post-treatment.

CONCLUSIONS

Bacteria located within the cheek, tongue mucosa, saliva, or untreated sites may contribute to reinfection of the pockets and explain the insignificant response to local tetracycline therapy.

The experience of endoscopic tissue glue injection in the treatment of hepatic sarcoidosis related gastric variceal bleeding: report of a case

A case of hepatic sarcoidosis complicated with portal hypertension and gastric variceal bleeding is described. A 53 year-old male suffered from persistent fever and massive hematemesis. Acute gastric variceal bleeding was diagnosed. Endoscopic tissue glue injection stopped this acute episode and ablated the varices after another two sessions of endoscopic tissue glue injection treatment. Subsequent administration of corticosteroids improved the symptoms and liver function. This was probably the first case of hepatic sarcoidosis associated with gastric variceal bleeding which was successfully treated by endoscopic tissue glue injection to be reported.

Abdominal aortic aneurysm compression is probably responsible for the recurrent episodes of acute pancreatitis: case report

An aged male with a known history of abdominal aortic aneurysm suffered from epigastralgia, vomiting and cold sweating for one day. According to the physical examination, serum amylase level and computed tomographic examination, acute pancreatitis was diagnosed. Surgical intervention for the abdominal aortic aneurysm was not performed because of his age, and finally this patient died after three recurrent episodes. Acute pancreatitis co-existing with an intact abdominal aortic aneurysm has never been reported before. The possible pathogenesis of this recurrent acute pancreatitis was discussed.

Preserved esophagogastric manometric motility in patients after distal gastrectomy

BACKGROUND/AIMS

A prospective study resolved whether commonly employed distal gastrectomies could influence the esophagogastric manometric measurements and the role of vasoactive intestinal polypeptide in mediating motility after surgery.

METHODOLOGY

Studied groups consisted of 20 patients following radical subtotal gastrectomy for gastric cancer, 20 patients after subtotal gastrectomy for duodenal ulcer and 20 controls. Fasting blood was obtained to measure serum vasoactive intestinal polypeptide levels. A pneumohydraulic infusion system measured esophagogastric motility parameters.

RESULTS

Measured lower esophageal sphincter pressures in subjects of gastric cancer surgery, duodenal ulcer surgery and controls were 15.3 +/- 4.7, 13.1 +/- 5.3 and 12.6 +/- 5.0 mmHg, respectively (NS), while the sphincter lengths were 3.15 +/- 0.81, 3.22 +/- 0.79 and 2.86 +/- 0.85 cm, respectively (NS). In addition, other parameters including lower esophageal body remained unchanged. The serum vasoactive intestinal polypeptide levels of three groups were 24.1 +/- 10.8, 22.5 +/- 9.5 and 21.3 +/- 7.8 pg/ml, respectively (NS).

CONCLUSIONS

Neither gastric cancer nor duodenal ulcer in distal stomach removal can alter the lower esophageal body and LES manometric motilities. Unchanged serum VIP levels after gastric surgery are likely one of the mechanisms preserving esophagogastric integrity.

Endothelin-1 is a candidate mediating intestinal dysmotility in patients with acute pancreatitis

We studied whether gastrointestinal transit was disturbed during acute pancreatitis and attempted to identify which mechanisms might be involved in acute pancreatitis. Using a noninvasive hydrogen breath test to determine the orocecal transit time, 24 patients with the clinical diagnosis of acute pancreatitis were enrolled into the intestinal motility study. Orocecal transit time was measured twice in all patients: once at the acute stage and once at recovery. Blood was obtained to study amylase, lipase, C-reactive protein, erythrocyte sedimentation rate, and endothelin-1 and nitrate/nitrite levels. Orocecal transit times measured at the acute stage were significantly delayed compared with those at recovery (mean values +/- SEM, 130.0 +/- 9.0 vs 80.8 +/- 7.4 min, P < 0.001). Plasma endothelin-1 levels exhibited a positive correlation with orocecal transit times in the acute stage (r = 0.509, P = 0.011). The percentages of altered orocecal transit times also correlated with the percentages of altered plasma endothelin-1 levels (r = 0.751, P < 0.001). Plasma nitrate/nitrite levels significantly decreased at the acute stage compared with those at recovery (5.25 +/- 0.82 vs 10.20 +/- 1.24 microM, P < 0.05). We conclude that intestinal transit is delayed in patients with mild to moderate acute pancreatitis. Elevated plasma endothelin-1 levels in the acute stage may be one mechanism mediating intestinal dysmotility.

Gastric inhibitory polypeptide appears less important in mediating acid secretion

BACKGROUND/AIMS

Gastric inhibitory polypeptide is recognized as an acid inhibitor, while its relationship with Helicobacter pylori colonization is unknown. The present study measured serum gastric inhibitory polypeptide levels in patients after various types of gastric resection and the influence of demographic characteristics including Helicobacter pylori on serum gastric inhibitory polypeptide levels.

METHODOLOGY

The study included twenty patients who underwent distal gastrectomy for duodenal ulcer, 33 patients who underwent radical subtotal gastrectomy for gastric carcinoma and 7 patients who underwent total gastrectomy. Another 58 healthy subjects served as controls. Their demographic characteristics were recorded, while serum gastric inhibitory polypeptide levels were measured using a homemade radioimmunoassay kit.

RESULTS

The serum gastric inhibitory polypeptide levels in the three patient groups and the controls were 246.2+/-38.7 pg/ml, 201.7+/-30.9 pg/ml, 183.5+/-34.5 pg/ml and 202.6+/-14.0 pg/ml, respectively. The difference among the four groups was not significant. Neither age, gender, body mass index, smoking, Helicobacter pylori colonization nor type of gastrectomy had an influence on serum gastric inhibitory polypeptide levels in the controls and the three patient groups. However, elapsed time since operation in patients following total gastrectomy exhibited a significant positive correlation with their gastric inhibitory polypeptide levels (r=0.89, p<0.05).

CONCLUSIONS

Serum gastric inhibitory polypeptide levels remain unchanged in patients undergoing various types of gastrectomy. Colonization of Helicobacter pylori does not influence its level. This peptide is probably less important in mediating gastric acid secretion.

The risk factors for gallstone disease among senior citizens: an Oriental study

BACKGROUND/AIMS

Few Occidental studies have addressed the risk factors for gallstone disease (GSD), among aged people. It is unknown whether these factors also present in the Orientals. Therefore, we studied the prevalence and risk factors for GSD among aged people in Taiwan.

METHODOLOGY

1441 aged subjects (> or = 60 years) who received a paid physical checkup at this hospital were investigated. Their demographic characteristics and biochemical parameters were recorded and compared. Ultrasonographic diagnosis revealed a normal gallbladder in 1092 subjects, gallbladder stones in 171, cholecystectomy for gallstones in 65, gallbladder polyps in 83, mixed gallbladder stones/polyps in 10, and miscellaneous results in 20. We enrolled 236 subjects showing either gallbladder stones or cholecystectomy for gallstones as the GSD group.

RESULTS

Excluding those subjects with mixed gallbladder stones/polyps, the overall prevalence of GSD in our series was 16.6%. Using multivariate analysis, the encountered factors manifesting risk for the development of GSD were old age (p<0.001), lower serum high-density lipoprotein level (p<0.01), diabetes mellitus (adjusted odds ratio: 2.127; p<0.001) and glucose intolerance (adjusted odds ratio: 1.954; p<0.001), whereas past history of alcohol consumption (adjusted odds ratio: 0.335; p<0.01) exhibited a protective effect against the development of GSD. Other demographic characteristics and biochemical parameters, such as body mass index, ABO blood type, cigarette smoking, blood pressure, serum cholesterol level, hepatitis B virus carrier, liver function, and parity, did not have any correlation to GSD.

CONCLUSIONS

Among the aged senior citizens in Taiwan, individuals with old age, lower serum high-density lipoprotein level, diabetes and glucose intolerance are at high risk for developing GSD.

[Protection of spinal motorneurons of section sciatic nerve by transplantation of NT-4 genetically expression cells into the side of section]

The NT-4 genetically engineered cells were made by infecting L-6TG cell (a rat myoblast cell line) in vitro with a retroviral vector pN2A containing the rat NT-4 cDNA. The bioactivities were determined by bioassay of PC12 cell survival rate. The rat with left sciatic nerve transaction was used as a model for treatment by implanting NT-4 genetically modified cell. The condition of motorneurons was assessed by Nissl stain and ChE stain. The results showed that: (1) the percentage of surviving Nissl-stained neurons on the lessened side of NT-4 (+) grafts significantly increased as compared to that with NT-4 (-) grafts 2-3 weeks and 3 months after sciatic nerve transaction, and (2) the grafted cells produced significant increase in the positive ChE stained area after sciatic nerve transaction in 1-3 weeks. Our observations indicate that adult motor neurons are still able to respond to neurotrophic factors and they may require the factors for survival.

Postprandial changes of sympathovagal balance measured by heart rate variability

The aim of this study was to investigate the sympathovagal balance after meals by measuring the spectral analysis of heart rate variability (HRV). Nine healthy volunteers were enrolled in this study. The electrocardiogram (ECG) was recorded for 30 min in a fasting state and 60 min after a 500-kcal test meal. The HRV was derived from the ECG and was measured by power spectral analysis using fast-Fourier transform algorithm. It reveals two dominant spectral components. The low-frequency (LF) band reflects primarily sympathetic activity with some parasympathetic input. The high-frequency (HF) band is a reflection of parasympathetic (vagal) activity. The LF-to-HF ratio is considered a marker of sympathovagal balance. It was found that the postprandial LF-to-HF ratio, compared with the fasting state, was significantly increased at both the first 30 min (2.50 +/- 0.49 vs 1.78 +/- 0.33, P < 0.05) and the second 30 min (2.68 +/- 0.55 vs 1.78 +/- 0.33, P < 0.05). The postprandial HF diminished significantly at both the first (16.0 +/- 0.5 vs 21.8 +/- 4.2, P < 0.05) and the second (13.8 +/- 9.5 vs 21.8 +/- 4.2, P < 0.05) 30-min period. In conclusion, the postprandial sympathovagal ratio shows a sustained elevation lasting 1 hr, mainly attributed to diminished vagal activity.

Clinical significance of portal lymphoid aggregates/follicles in Chinese patients with chronic hepatitis C

OBJECTIVE

Portal lymphoid aggregates/follicles (lymphoid A/F) is a characteristically histological finding in patients with chronic hepatitis C. We assessed the prevalence of lymphoid A/F in Chinese patients with chronic hepatitis C and evaluated the correlation of this phenomenon with clinical, biochemical, immunological, virological, and other histological features of these patients.

METHODS

Eighty-nine Chinese patients with chronic hepatitis C were enrolled and portal lymphoid A/F was evaluated in liver biopsy. Clinical, biochemical, immunological, histological, and virological data, including serum HCV RNA titer and HCV genotype and the response to interferon therapy, were compared between patients with and without portal lymphoid A/F.

RESULTS

Twenty-nine (33%) of 89 patients with chronic hepatitis C had portal lymphoid A/F. Patients with lymphoid A/F had a significantly higher frequency of HCV genotype 1b infection (p = 0.039) and had a significantly higher mean score of bile duct damage, periportal necroinflammation, and portal inflammation in liver histologies when compared with patients without lymphoid A/F. No significant difference in sex distribution, mean age, history of blood transfusion, serum liver biochemistry, presence of serum autoantibodies/cryoglobulinemia, serum viral titer, and response to interferon therapy was noted between the two groups. Multivariate logistic regression analysis showed HCV genotype 1b infection and periportal necroinflammation were significant independent predictors associated with portal lymphoid A/F.

CONCLUSIONS

The presence of portal lymphoid A/F in Chinese patients with chronic hepatitis C was significantly correlated with HCV genotype 1b infection and periportal necroinflammation.

Supportive treatment, resection and transcatheter arterial chemoembolization in resectable hepatocellular carcinoma: an analysis of survival in 419 patients

OBJECTIVE AND DESIGN

Both surgical resection and transcatheter arterial chemoembolization (TACE) are effective treatments for hepatocellular carcinoma (HCC). Few reports have compared the different treatment modalities for resectable HCC based on clinically matched groups. The aim of this study was to compare the survival rate after surgery, TACE or supportive treatment in resectable HCC patients, and also in elderly patients (> or = 70 y/o).

METHODS

From 1984 to 1993, 419 consecutive patients with resectable HCC were included in this study. Of these, 311 (74%) underwent resection of tumours and 46 (11%) refused operation, opting instead for TACE. The remaining 62 (15%) who refused both methods of treatment were given supportive care. Univariate and multivariate analyses for prognostic factors and the 5-year survival rate among the groups were studied.

RESULTS

Both surgical resection and TACE groups had a better 5-year survival rate than the supportive treatment group (43% and 34% vs. 7%). There was no difference in survival between the surgery and TACE groups. However, the 5-year survival rate was 11% in TACE and 41% in the surgical group when the patients were > or = 70. In multivariate analysis, female sex (P = 0.0466), tumour size < or = 3 cm (P = 0.0001), alpha-fetoprotein (AFP) < 400 U/l (P = 0.0036), single tumour (P = 0.0474), serum creatinine < or = 1.5 mg/dl (P = 0.0006) and alkaline phosphatase (AP) < or = 100 U/l (P = 0.0007) are associated with good prognosis for resectable HCC.

CONCLUSION

TACE is an alternative for resectable HCC. Tumour size, tumour number, AFP level, renal function, AP level and female sex are prognostic factors. In elderly people, TACE must be used prudently and has a worse prognosis.

Relationship of the subgingival microbiota to a chairside test for aspartate aminotransferase in gingival crevicular fluid

BACKGROUND

The aim of the present study was to evaluate the association between the occurrence of certain specific periodontal pathogens and aspartate aminotransferase (AST) levels in gingival crevicular fluid (GCF).

METHODS

Thirty systemically healthy subjects with moderate to advanced periodontitis were selected. Within each subject, the AST contents of GCF from sites with probing depth between 5 mm and 7 mm were measured using a chairside colorimetric test. AST-positive site refers to one that had an AST level > or = 800 microIU. Subgingival plaque samples from one AST-positive and one negative site were collected for microbiological examination. One site with probing depth < or = 3 mm and no gingival inflammation was selected as a healthy control. Clinical parameters of the chosen sites, including the plaque index and gingival index scores, probing depth, and clinical attachment level were measured. Culture and immunofluorescence (IF) were used for detecting common periodontal pathogens, including Actinobacillus actinomycetemcomitans, Peptostreptococcus micros, Campylobacter rectus, Eikenella corrodens, Fusobacterium nucleatum, Capnocytophaga species, Prevotella intermedia, Prevotella melaninogenica, and Porphyromonas gingivalis. Logistic regression was used to analyze the correlation between the AST test and certain specific pathogens.

RESULTS

The GCF scores and total cultivable bacterial counts were higher in AST-positive sites than either AST-negative or healthy sites. The prevalence and proportions of specific periodontal pathogens such as C rectus, E. corrodens, F. nucleatum, Capnocytophaga species, P. intermedia, and P. gingivalis were significantly higher in positive than in negative sites. In analyzing the correlation of the proportion of 6 pathogens with the AST test by logistic regression, only P. gingivalis showed a significant positive correlation. The odds ratio of having a high proportion of P. gingivalis in the presence of a positive AST test was 1.21.

CONCLUSIONS

The present study showed that at AST-positive sites, there is a higher prevalence and higher proportion of certain periodontal pathogens. Although only the correlation of P. gingivalis and AST values was statistically significant, the results imply that certain periodontal pathogens may be associated with elevation of AST levels in GCF.

Gastric myoelectrical activity in patients with cervical spinal cord injury

OBJECTIVE

Dyspeptic symptoms are common in patients with cervical spinal cord injury (SCI). The supraspinal control of sympathetic innervation to the stomach is interrupted in these patients. Gastric emptying has been reported to be delayed in some patients with cervical SCI. Gastric myoelectrical activity is known to regulate gastric motility and is correlated with gastric emptying. The change in gastric myoelectrical activity after cervical SCI is unknown; our aim was to investigate it.

METHODS

The study was performed in 12 cervical SCI patients and 14 healthy controls. Gastric myoelectrical activity was recorded using surface electrogastrography for 30 min in the fasting state and 1 h after a standard test meal. Spectral analysis was performed to compute the following parameters from the electrogastrogram; investigated were the percentage of 2-4 cycles/min (cpm) slow waves, the instability coefficient (IC) of the dominant frequency, the postprandial increment of dominant frequency (deltaF), and its power (deltaP).

RESULTS

In both fasting and fed states, regular and stable gastric slow waves were observed in both the control group and patients with cervical SCI. The percentage of normal 2-4 cpm slow waves (preprandial, 80.7+/-3.6% vs 91.5+/-3.7%, p > 0.05; postprandial, 82.0+/-4.4% vs 87.2+/-4.2%, p > 0.05) and IC (preprandial, 0.19+/-0.04% vs 0.28+/-0.05%; postprandial, 0.24+/-0.04% vs 0.27+/-0.02%, p > 0.05) were not significantly different between the two groups. The dominant frequency and its power were also similar between the two groups, no matter whether in the fast (frequency, 2.92+/-0.3 vs 2.93+/-0.06 cpm; power, 30.05+/-1.29 vs 29.08+/-1.23 dB, p > 0.05) or fed (frequency, 3.17+/-0.07 vs 3.02+/-0.06 cpm; power, 32.55+/-0.90 vs 32.07+/-1.18 dB,p > 0.05) state. The postprandial response measured by deltaF (0.25+/-0.09 vs 0.09+/-0.07 cpm, p > 0.05) and deltaP (2.52+/-1.10 vs 2.24+/-1.20 dB, p > 0.05) were also similar between the two groups.

CONCLUSION

Gastric myoelectrical activity was not altered after cervical SCI.

Levels of immunoreactive dynorphin A1-13 during development of morphine dependence in rats

AIM

To study the relationship between the levels of immunoreactive dynorphin A1-13 (ir-dynorphin A1-13) and the degree of morphine dependence.

METHODS

The levels of ir-dynorphin A1-13 in discrete brain regions, spinal cord, and plasma in rats were determined by radioimmunoassay, and the degree of morphine dependence was assessed by scoring withdrawal signs on d 3, d 6, and d 12.

RESULTS

Morphine injection s.c. decreased the levels of ir-dynorphin A1-13 in spinal cord, pituitary, and plasma. The levels of ir-dynorphin A1-13 in hippocampus and hypothalamus were increased. No changes in cortex, midbrain, cerebellum, pons, and medulla were observed. With continuous injection of morphine, withdrawal signs scores were increased on d 6, but there was no difference between the scores of d 6 and d 12.

CONCLUSION

The changes of the levels of endogenous ir-dynorphin A1-13 in pituitary, spinal cord, and plasma were compatible with the degree of morphine dependence.

An improved electrogastrographic system in measuring myoelectrical parameters

This study assessed the reliability of an improved electrogastrographic (EGG) system in recording stomach myoelectrical parameters and tried to establish the normal ranges of myoelectricity using this system. The analytical software of the current system mainly included an autoregressive modelling program to compute myoelectrical frequency and power. Forty healthy subjects were enrolled to receive myoelectrical measurement in two consecutively fasting and one postprandial 30 min sessions. The myoelectrical frequencies in both fasting and postprandial sessions were almost three cycles per min (c.p.m.) and showed little variation. The percentage of dominant frequencies (2.5-3.5 c.p.m.) in three sessions was approximately 80% while the computed myoelectrical powers in the first and second fasting sessions exhibited a significant correlation (r=0.84, P<0.001). Meal ingestion increased the myoelectrical powers by 6.8dB compared with the second fasting recording (P< 0.001). The mean variation in myoelectrical amplitude for the ratio of second: first fasting session was 110.3+/-88.8% (16-478%, median 88%). This new EGG system is, indeed, reliable for measuring myoelectrical frequency and power, whereas the interassay of recorded amplitudes appears markedly variable.

The molecular basis for bidirectional communication between the immune and neuroendocrine systems

IL-2 has analgesic effects in both central and peripheral nervous systems. There are two distinct domains in IL-2 molecule mediating immunologic and analgesic activity, respectively. The analgesic domain of IL-2 may be composed of the 44th Phe, 45th Tyr, 107th Tyr, and 117th Phe residues that are located closely in the tertiary structure of IL-2. The analgesic activity may be mediated through the analgesic domain interaction with opioid receptor. In addition to peptides, cytokines may directly bind to peptide receptors, other than their specific cytokine receptors themselves. Conversely, peptides may also interact with cytokine receptors. Thus, peptide neurotransmitters and hormones may serve as endogenous regulators of the immune system, and cytokines may also serve as neurotransmitters. Multiple actions might be mediated by interactions between distinct domains of bioactive molecules with different receptors.

Abnormal vagal cholinergic function and psychological behaviors in irritable bowel syndrome patients: a hospital-based Oriental study

Irritable bowel syndrome (IBS) patients in Western countries usually manifest autonomic nerve dysfunctions and abnormal psychological behaviors. The purpose of this study was to assess whether Oriental IBS patients with predominant bowel symptoms also exhibited similar abnormalities. We enrolled 40 IBS patients from the outpatient clinic and 20 controls with normal daily bowel habit for study. The IBS patients were further divided according to their predominant bowel habit: 20 were constipation-predominant and 20 were diarrhea-predominant. Sympathetic function was evaluated by sympathetic skin response (SSR) while vagal cholinergic function was determined by measuring R-R interval variation (RRIV) in electrocardiography during rest and deep breathing. Psychological parameters were assessed by scales of the Minnesota Multiphasic Personality Inventory (MMPI) and the Hopkins Symptom Checklist (HSCL-90). IBS patients, despite their bowel habit, showed normal SSR response. RRIV during deep breathing was significantly lower in constipation-predominant IBS patients than in controls or diarrhea-predominant IBS patients (16.5+/-3.1% vs 20.5+/-4.8% and 21.5+/-4.6%, P < 0.001). IBS patients also exhibited abnormal MMPI measuring scores on depression, hysteria, paranoia, and masculinity/femininity scales. In addition, they also had more severe psychological distress in the items of HSCL-90 measurement. In conclusion, vagal dysfunction characterizes Oriental constipation-predominant IBS patients seeking medical help. Abnormal psychoneurotic profiles also exist in these IBS patients, irrespective of their bowel habits.

Characteristics of small bowel motility in patients with irritable bowel syndrome and normal humans: an Oriental study

1. Small bowel dysmotility may be one of the clinical manifestations in Occidental patients with irritable bowel syndrome. Here we studied the characteristics of small bowel motility in Oriental patients with irritable bowel syndrome and identified the factors responsible for disturbed small bowel motility. 2. We enrolled 90 patients with irritable bowel syndrome and 45 healthy controls to the study. The patients with irritable bowel syndrome were further divided according to their predominant bowel habits. Of those, 45 were constipation-predominant and 45 were diarrhoea-predominant. Small bowel transit was measured by the non-invasive hydrogen breath test in the fasting state. 3. The transit times obtained in constipation-predominant and diarrhoea-predominant patients with irritable bowel syndrome and in controls were 108.4+/-34.3, 67. 4+/-19.6 and 85.3+/-37.3 min respectively (P<0.05). Delayed transit characterized constipation-predominant patients with irritable bowel syndrome, whereas accelerated transit was observed in diarrhoea-predominant patients with irritable bowel syndrome. The ages of constipation-predominant and diarrhoea-predominant patients with irritable bowel syndrome and of controls displayed a significant positive correlation with their small bowel transit times (r=0.34, 0.31 and 0.39 respectively; P<0.05) and body mass indexes also demonstrated a positive correlation (r=0.31, 0.41 and 0. 30 respectively; P<0.05). Other demographic characteristics did not influence the small bowel transit times. 4. Accelerated or delayed small intestinal transit is exhibited in Oriental patients with irritable bowel syndrome showing either diarrhoea-predominant or constipation-predominant symptoms. Age and body mass index must be taken into consideration to study patients with suspected small intestinal dysmotility.

Clinical response of localized recurrent periodontitis treated with scaling, root planing, and tetracycline fiber

The purpose of this study was to compare the clinical efficacy of scaling and root planing alone versus tetracycline fiber therapy used adjunctively with scaling and root planing in the treatment of nonresponsive active periodontitis in patients under supportive periodontal therapy. Thirty patients who were receiving supportive treatment and had at least two nonadjacent periodontitis sites with a probing depth of between 4 and 8 mm and bleeding on probing, or had aspartate aminotransferase (AST) levels above 800 microIU in the gingival crevicular fluid in separate quadrants participated in this study. For each patient, the test sites were treated with scaling and root planing plus tetracycline fibers while the control site was treated with scaling and root planing only. Probing depths, clinical attachment levels, gingival recession, AST levels, and bleeding on probing were recorded and subgingival plaque samples were collected at baseline and 1, 3, and 6 months following treatment. At 3 months after treatment, there was a reduction of bleeding on probing and probing depth, and a gain of clinical attachment in both test and control sites. The mean reduction in probing depth of the test sites was 1.38 mm and the attachment gain was 0.8 mm after 6 months. The clinical response obtained at 3 months following therapy was maintained throughout the 6-month follow-up period. However, there were no statistically significant differences between sites treated with scaling and root planing alone and those treated with combined tetracycline therapy. Most of the reductions of probing depths in the fiber group were attributed to gingival recession. The present study did not confirm the efficacy of adjunctive tetracycline fibers in treating nonresponsive sites in maintenance subjects with regard to probing depth reduction or clinical attachment gain. Reinfection of the pockets from untreated sites and extra-crevicular regions may explain the insignificant response to local tetracycline therapy.