Craniofacial pattern of young adults with various types of malocclusion

Craniofacial morphological characteristics of young adults with various malocclusions were investigated. Cephalometric radiographs of 100 Class I, 100 Class II, and 100 Class III cases were selected and subjected to counterpart analysis as described by Enlow. Results of individuals with normal occlusion revealed a mean value of 38.75 degrees for the angle of the middle cranial fossa relative to the posterior maxillary plane alignment (MCF/PM). This value was used as the basis for intrinsic alignment comparisons for all the other various parts. Classes I and II malocclusions were classified as either type A or B, depending on whether point A or B was protrusive in the functional occlusal plane (FOP). We found that type B was more common for Class I malocclusion. Further, these cases exhibited an underlying Class III character. We also noted that B groups had different structural craniofacial patterns relative to those seen in A groups. The difference between Class IA and Class IIA, or between Class IB and Class IIB was slight but quantitative. Class III and Class IIA individuals had distinctly different and essentially opposite underlying patterns. However, the composite compensatory result in Class IB case was, for the most part, effective.

Time-frequency spectral analysis of heart rate variability during induction of general anaesthesia

We have examined the spectral components of heart rate variability (HRV) during induction of anaesthesia with thiopentone, tracheal intubation and subsequent inhalation of isoflurane-nitrous oxide. Commonly used spectral analysis methods such as fast Fourier transformation or autoregressive modelling require stationary data and are not suitable for the rapidly changing HRV data in this period. An advanced spectral analysis method, time-frequency analysis, which can treat non-stationary data, was used in this study. Multiple spectra were generated to demonstrate the time-related spectral components of HRV. Mid-frequency power (MF, 0.08-0.15 Hz), high-frequency power (HF, 0.15-0.5 Hz) and MF/HF ratio at baseline, after induction (before intubation), immediately after intubation and during maintenance periods were calculated and compared. MF and HF powers decreased after induction and were reduced further in the maintenance period but MF/HF ratio remained unchanged after induction. Immediately after intubation MF and HF powers did not differ significantly from the immediate pre-intubation values, but MF/HF ratio did.

Elimination of interference component in Wigner-Ville distribution for the signal with 1/f spectral characteristic

A new technique for interference-term suppression in Wigner-Ville distribution (WVD) is proposed for the signal with 1/f spectrum shape. The spectral characteristic of the signal is altered by f alpha filtering before time-frequency analysis and compensated after analysis. With the utilization of the proposed technique in smoothed pseudo Wigner-Ville distribution, an excellent suppression of interference component can be achieved.

Cytotoxic effects of anthrax lethal toxin on macrophage-like cell line J774A.1

The cytotoxic effects of anthrax lethal toxin purified from an avirulent strain were examined on mouse macrophage-like J774A.1 cells. Cell death induced by high concentration of purified lethal toxin had the characteristics of necrosis. At lower concentrations, the toxin caused no morphological change and most of the cells were viable. Interestingly, apoptotic cells were observed when the cells were preincubated with a serine/threonine phosphatase inhibitor, calyculin A, and then exposed to a toxin concentration of 0.1 microg/ml. This is the first report that lethal toxin of the anthrax bacillus can induce both necrosis and apoptosis and that protein phosphatases are implicated in the regulation of bacterial toxin-induced apoptosis.

Testicular blood flow following spinal cord injury in the Sprague Dawley rat

The causes of poor semen quality following spinal cord injury (SCI) are unknown. One possible mechanism is decreased testicular blood flow. Chronic testicular ischemia in non-SCI animals has been shown to have significant adverse impact on spermatogenesis. This study was designed to evaluate testicular blood flow following SCI in the Sprague Dawley rat. Testicular blood flows were determined in 11 rats with SCI at thoracic level nine (T9) and six sham control rats three days prior and three days and 14 days after SCI. Testicular blood flow velocity was measured with a Doppler flow probe. Blood flows were compared between groups using T-tests. There were no significant changes in blood flow in the sham operated rats three or 14 days after surgery. However, three days after SCI, blood flow had decreased in the SCI rats to 78 +/- 5 percent of the pre-SCI flow (t = -4.65 with 10 df, p < 0.001). At 14 days after SCI, blood flow was still decreased to 77 +/- 8 percent, (t = -3.40 with 3 df, p < 0.05). This study established that following SCI, testicular blood flow decreases in the Sprague Dawley rat.

Blood and central venous pressure responses after serial tourniquet deflation during bilateral total knee replacement

Thirty-five patients who underwent one-stage bilateral total knee replacement were included in this study to determine whether there was any difference in hemodynamic effects following the deflation of the first and second tourniquets. The values of hemodynamic variables were not significantly different immediately before either the first or the second tourniquet release as compared to preoperative values. The changes in heart rate after the release of the first and second tourniquets showed similar patterns. The systolic and diastolic blood pressure decreased significantly after deflation of the first and second tourniquets. However, the decrease was more marked after the second tourniquet deflation. The level of central venous pressure decreased significantly after the release of the first and second tourniquets but the patterns of change were not significantly different. The need for administration of ephedrine was also higher after the deflation of the second tourniquet than after the first. We conclude that the blood pressure changes after the second tourniquet deflation are more pronounced than those following the first tourniquet deflation. Anesthesiologists must be aware of this phenomenon and prevent marked hemodynamic changes that could be detrimental to high-risk patients.

Perioperative changes of plasma endothelin-1 concentrations in patients undergoing cardiac valve surgery

Twenty-one patients who underwent cardiac valvular replacement procedures were studied to determine the perioperative changes of plasma endothelin-1 (ET-1) concentration and disposition of ET-1 in the pulmonary and systemic vasculature between patients with elevated (over 20 mmHg) mean pulmonary artery pressure and patients with normal pulmonary artery pressure. The overall profile alterations of plasma ET-1 concentration did not differ between the two groups of patients. The plasma ET-1 levels in the pulmonary artery and right atrium were significantly higher in patients with high pulmonary artery pressure than in patients with normal pulmonary artery pressure. Before cardiopulmonary bypass, significant pulmonary extraction of the plasma ET-1 existed in patients with high pulmonary artery pressure but the pulmonary extraction was not seen after bypass. There was no transpulmonary difference of the plasma ET-1 concentration in patients with normal pulmonary artery pressure either before or after bypass. The high levels of ET-1 in the pulmonary circuit and the pulmonary extraction of the ET-1 in patients with high pulmonary artery pressure might be a protective mechanism for rheumatic valvular patients with elevated pulmonary artery pressure.

The effect of cerebrospinal fluid dilution of isobaric 0.5% bupivacaine used for spinal anaesthesia

A prospective study was conducted to see the effect on spinal anaesthesia of the dilution of isobaric 0.5% bupivacaine with cerebrospinal fluid. Sixty patients were randomly allocated to three groups. In group 1, patients received 3 ml isobaric 0.5% bupivacaine intrathecally without aspirating cerebrospinal fluid. In groups 2 and 3, cerebrospinal fluid 1 ml and 2 ml was aspirated respectively and mixed with 3 ml isobaric 0.5% bupivacaine. A total volume of 4 ml in group 2 and 5 ml in group 3 was administered. Thus, the volume of cerebrospinal fluid remained unchanged. Pinprick analgesia and motor block was evaluated from induction until recovery. No differences in onset time, duration and 'two segments regression' were noticed. The only statistical difference was the time to reach complete motor block, which was shorter in group 1 as compared to groups 2 and 3 (6.9 SD 1.4 min versus 11.3 SD 3.0 and 13.5 SD 3.9 min respectively). The mean value of maximum decrease in systolic blood pressure was small, being less than 15% of the pre-operative value for each group. In conclusion, the effect of diluting isobaric 0.5% bupivacaine with cerebrospinal fluid, 1 ml and 2 ml, is minimal and it is an unnecessary procedure with limited clinical effect.

Role of urinary cytology and urinary deoxyribonucleic acid flow cytometry in the diagnosis of bladder cancer

In order to determine the diagnostic efficiencies of urinary cytology and urinary deoxyribonucleic acid (DNA) flow cytometry (FCM) in the detection of bladder cancer, 92 patients were studied from March 1991 to the end of July 1992. Thirty cases had previously undergone operation for bladder cancer and 62 cases were suspected as bladder cancer. One to three fresh voided urine samples from the same patient were sent for conventional urinary cytology and urinary DNA FCM analysis. Each patient underwent cystoscopic examination or surgical histopathologic examination to verify the presence of bladder tumor. From December 1991 to the end of July 1992, 52 cases were analyzed and reported separately due to improved FCM techniques. Urinary DNA FCM showed a higher sensitivity than cytology in both the total (p < 0.05) and the second half time period (p < 0.01). Cytology showed a statistically superior specificity against FCM in the total period (p < 0.05) but not in the second half time period (p > 0.1). Combining sensitivity and specificity, FCM's overall accuracy rate was better than cytology in the second half time period (p < 0.05). To clarify the specific features of bladder tumors in which FCM showed superior sensitivity than cytology, we analysed the detection rates for various features of bladder tumor in the second half time period. FCM was better than cytology in detecting multiple tumors, small tumors and papillary tumors. No statistical differences were obtained if tumors were single, larger than 3 cm or flat in outer surface. To our knowledge, no previous similar analysis has been reported in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Validity and feasibility of nasopharyngeal end-tidal carbon dioxide tension monitorings: a novel approach in spontaneous breathing patients

Conventional end-tidal CO2 (Pe'CO2) monitoring is difficult and impractical in nonintubated patients who are either sedated or anesthetized while spontaneous respiration is maintained. An alternative technique using nasopharyngeal end-tidal carbon dioxide tension (PNe,CO2) has been developed. The present study evaluates the feasibility and validity of PNe,CO2 as a reliable respiratory monitoring method. Sixty patients in ASA class status I or II and scheduled for elective surgery were divided into two groups. In group 1 (n = 30), conventional Pe'CO2 was used in intubated patients under general anesthesia. In group 2 (n = 30), PNe,CO2 monitoring was used in patients under regional anesthesia with spontaneous respiration maintained. A 12 FG suction catheter, connected to the sampling tube of a CO2 analyzer, was inserted via the nasal airway to within 1 cm of the nasopharyngeal orifice. Arterial blood gas (PaCO2) was sampled 25 minutes after the operation began, Pe'CO2 (group 1) and PNe,CO2 (group 2) were recorded simultaneously. In both groups, PaCO2 was highly correlated with Pe'CO2 (r = 0.6938) and PNe,CO2 (r = 0.8613). The difference between the two values, (a-e')PCO2 = 0.35 +/- 0.33kPa and (a-Ne')PCO2 = -0.1 +/- 0.51kPa, indicates that PNe,CO2 is more closely correlated to PaCO2 than conventional Pe'CO2. The reduced (a-Ne')PCO2 in group 2 may be explained by CO2 rebreathing and a reduced respiratory deadspace during anesthesia and spontaneous breathing. Interestingly, 60% of the (a-Ne')PCO2 measurements were negative values, suggesting that PNe,CO2 and a spatial V/Q mismatch is caused by sedation; higher CO2 production and CO2 rebreathing may explain the results.(ABSTRACT TRUNCATED AT 250 WORDS)

Differences in temperature changes between pediatric and adult patients after cardiopulmonary bypass

Nasopharyngeal (NPT) and rectal (RT) temperatures were continuously monitored in 51 adult or pediatric patients undergoing cardiac surgical procedures until 1 hour after the termination of cardiopulmonary bypass (CPB). The measurement also included the lowest NPT achieved and the dwelling time at that temperature on CPB, the rewarming time, the time on CPB, and the time that the chest remained opened after CPB. After the termination of CPB, the decrease of NPT (afterdrop) was significantly greater in the adult group than in the pediatric group. The mean decrease in adult patients was 1.34 +/- 0.65 degrees C versus 0.63 +/- 0.8 degrees C in pediatric patients. The combination of the NPT at the end of bypass (EndNPT), body weight times the EndNPT, and the dwelling of the lowest temperature times the EndNPT could predict 45% of the afterdrop. It is concluded that afterdrop occurs to a lesser degree in pediatric patients than in adults. This may be due to more efficient supplying of external heat to pediatric patients in whom there is a larger body surface area to weight ratio.

Polymerase chain reaction to detect human cytomegalovirus in livers of infants with neonatal hepatitis

Neonatal hepatitis is closely related to human cytomegalovirus infection in Taiwan, a conclusion based on serological and urine culture studies. To obtain more direct evidence further relating cytomegalovirus to the pathogenesis of neonatal hepatitis, the cytomegalovirus genome was studied in the liver tissues of 50 infants with neonatal hepatitis using the polymerase chain reaction (PCR). Liver tissues from 26 infants with biliary atresia and another 30 infants and children with diagnoses other than neonatal hepatitis, cholestasis, or hepatitis were also studied for comparison. Sequences from the immediate early gene 1 and 2 regions were used as primers. The liver tissues from 23 (46%) of the 50 infants with neonatal hepatitis were positive for cytomegalovirus genome, whereas those of 2 of the 26 infants with biliary atresia and none of the liver tissues from 30 infants and children without neonatal hepatitis were positive for cytomegalovirus genome, by PCR. The results of PCR correlated well with that of serology and urine culture. This study provides further evidence of cytomegalovirus in the pathogenesis of neonatal hepatitis.

Dietary soybean isolate and methionine supplementation affect mammary tumor progression in rats

The effect of feeding soybean protein isolate (SBP) diet or soybean protein isolate diet supplemented with 0.7% DL-methionine (SBP + Met) on mammary tumor progression was investigated. Sprague-Dawley female rats were fed from weaning a 20% casein (CAS) diet supplemented with 0.3% DL-methionine (AIN-76) and injected via jugular vein with N-nitrosomethylurea (NMU, 40 mg/kg body weight) at 7 wk of age. Five weeks after NMU treatment, animals were divided into the three isoenergetic, isoprotein diet groups: CAS (25 rats); SBP (26 rats) and SBP + Met (25 rats). First palpable mammary tumors were evident 8, 9 and 13 wk and the mean latency period was 13.30 +/- 1.23, 16.70 +/- 1.32 and 17.82 +/- 1.28 wk after NMU treatment in the CAS, SBP + Met and SBP diet groups, respectively. Tumor incidence was 80% in the CAS group compared with 42.3% in the SBP group (P = 0.01). Methionine supplementation increased tumor incidence to 64%. Total number and total weight of tumors was greater in the CAS group compared with either SBP + Met or SBP groups: 41 vs. 28 or 21 tumors and 97.28 g vs. 27.87 or 32.46 g, respectively. These data indicate that SBP diet, low in methionine content, fed 5 wk after carcinogen exposure significantly repressed mammary tumor progression. Methionine supplementation increased the number of animals with tumors but not the mean tumor weight.

Epidemiologic characteristics and multiple risk factors of stomach cancer in Taiwan

Both descriptive and analytical studies were carried out to examine epidemiologic characteristics and multiple risk factors of stomach cancer in Taiwan. The age-adjusted mortality rate of stomach cancer has been decreasing since the early 1970s for both males and females. The male-to-female ratio of the disease has remained around 2:1 in the past three decades. Comparison of the incidence of stomach cancer among Chinese in different countries showed a much lower incidence among Chinese in the USA than those in southeastern Asia. A hospital-based matched case-control study carried out in Taipei metropolitan areas showed a positive association of stomach cancer with blood type A, chronic gastric diseases, cigarette smoking, alcohol drinking, green tea drinking as well as consumption of salted meat, cured meat, smoked food, fried food and fermented beans. There was also a significant negative association between the disease and the consumption of milk.

Epidemiologic characteristics and multiple risk factors of lung cancer in Taiwan

The specific aim of this study was to examine epidemiologic characteristics and multiple risk factors of lung cancer in Taiwan. The age-adjusted mortality from lung cancer has been increasing since the early 1950s with a constant male-to-female ratio of around 2.0. International comparison of cumulative mortality from lung cancer showed a much lower male-to-female ratio in Chinese than in other populations. Significantly high mortality from lung cancer was observed in highly urbanized cities and the endemic area of chronic arsenicism in Taiwan. Significant associations of active and passive cigarette smoking with epidermoid carcinoma, small cell carcinoma and adenocarcinoma of the lung were observed in a hospital-based case-control study carried out in Taipei metropolitan areas. Alcohol drinking, coffee drinking and various types of indoor air pollution were not related to lung cancer after the cigarette smoking habit was adjusted through a multiple logistic regression analysis.

Suppression of hemodynamic change before extubation--lidocaine through modified endotracheal tube

Twenty females, aged 31 to 49 years, scheduled for abdominal total hysterectomy were randomly divided into two groups in this study. An epidural catheter was placed at T11-12 before general anesthesia. All patients receive the combination of epidural anesthesia and general anesthesia for the operation and relief of pain postoperatively. The modified endotracheal tube we used is shown in Fig. 1. For patients in group I (Lidocaine group), 2 mL 4% lidocaine solution was injected through the catheter to desensitize the tracheal mucosa around the cuff after the surgeon had removed the uterus. In group II (Control group), no special management was made. All patients were not extubated until they were considered to be awake. Systolic blood pressure at three and one minute before extubation and pulse rate recorded at one minute before extubation showed in patients of group I were statistically smoother than those recorded in group II (p less than 0.01). All patients had gag reflex just after awake extubation.

Community-wide epidemiological investigation of a typhoid outbreak in a rural township in Taiwan, Republic of China

An outbreak of typhoid fever occurred in Chu-Tung township, Taiwan, with dates of onset from 6 July to 8 August, 1983. Fifty-four cases were hospitalized, of which 52 were laboratory confirmed. A chloramphenicol-resistant strain of Salmonella typhi was isolated from patients' blood samples. A community survey of 2772 people selected from 490 households by stratified systematic cluster sampling, presented an attack rate of 9.4 per 1000 and a case reporting rate of 10%. The attack rate was higher in males than females for persons younger than ten years, but was greater in females than in males aged 40 years and older. The only consistent characteristic of the early outbreak cases was drinking of tapwater (10/10, 100% versus 319/490, 65% of the controls). None of the early cases but 36% (13/36) of the late cases had drunk stream or river water. Households of early cases had better hygienic conditions than those of late cases. Laboratory examination of environmental specimens indicated Escherichia coli contamination of tapwater, well water and all stream foci associated with human activities. The epidemiological data combined with laboratory results suggested that the epidemic might be due to repeated contamination of some common source (such as municipal tapwater) and/or a variety of other vehicles.

Restoration of sexual function and fertility by fetal hypothalamic transplant in impotent aged male rats

The purpose of this study was to observe whether fetal hypothalamic transplant can restore the neuroendocrine and reproductive function in impotent aged male rats. Eighteen to 20 month old impotent male rats received an anterior hypothalamus removed from a 17-19 day old fetus and placed into the anterior third ventricle. Controls were either without surgery (UC) or grafted with cerebral cortex (CG). Before and 2 to 3 months after transplantation, blood samples were collected from the aged rats for testosterone and LH measurement. Before and one to two months after transplantation, each hypothalamic grafted animal (HG) or control rat was put overnight into a cage which contained four, 10 to 12 week old proestrous female rats. Vaginal smear of each female was monitored early the next morning. Sperm seen in the vaginal smear was regarded as copulation and ejaculation. The test was repeated twice, one week apart, and the higher score represented the sexual function and fertility of the males. Seven of 10 HG males restored their sexual function, impregnated 9 females and fathered 106 pups. None of 7 UC restored their reproductive function and only one of 4 CG males impregnated one female which delivered 6 pups. Serum testosterone, LH and pituitary LH in the HG rats, which showed restoration of reproductive function, were significantly higher than those of the controls (UC and CG). These results indicate that the fetal hypothalamic grafts can survive and develop in the brain of impotent aged male rats and restore neuroendorince and reproductive function in senescent rats.

Dietary protein, enhancement of N-nitrosomethylurea-induced mammary carcinogenesis, and their effect on hormone regulation in rats

The effect of supplemental dietary protein (casein) fed with high fat diets was investigated using the N-nitrosomethylurea-induced mammary tumor model. Isocaloric diets containing casein and corn oil at 19 and 15% (normal protein-high fat) or 33 and 15% (high protein-high fat) were fed ad libitum to Sprague-Dawley mother rats. Female offspring continued on the diet. Food consumption and growth curves were similar over the entire growth period. N-Nitrosomethylurea (50 mg/kg body weight) or saline was administered at 7 and 8 weeks of age via the tail vein. Dietary protein had no effect on serum prolactin or growth hormone throughout the estrous cycle: Prior to carcinogen administration, at 7 weeks old, proestrus at 5 p.m., serum prolactin was 231.6 +/- 141.0 (SE) ng/ml (12 rats) versus 292.2 +/- 141.0 (13 rats) for normal versus high protein diet groups, respectively. No difference was noted after carcinogen injection at 9, 13, 28, and 33 weeks of age. Similarly no effect was noted on serum growth hormone activity. Tumor latency was 7 weeks and incidence was 100% in normal protein (24 rats) and high protein (39 rats) groups 28 weeks after carcinogen treatment. The number of tumors per rat (4.38 +/- 0.37 versus 2.87 +/- 0.35, P less than 0.002) and average tumor weight (17.97 +/- 2.63 versus 9.94 +/- 2.92 g) were significantly greater in the high protein group. Study indicates that diet or carcinogen treatment did not alter hormone regulation during the estrous cycle. However, supplemental dietary protein increased the effect of high fat diets enhancing the mammary tumor burden.

Effect of dietary protein on morphologic development of rat mammary gland

Isocaloric diets, containing 8% casein [low protein (LP)], 19.5% casein [normal protein (NP)], or 31% casein [high protein (HP)] and 10% corn oil, were fed to adult virgin female Sprague-Dawley rats prior to conception and were continued through mating, gestation, and lactation. Female pups, 8 per litter, were fed on their mother's diet for the duration of the study. The pups' sexual maturation occurred at 33, 35, and 70 days of age for the HP, NP, and LP groups, respectively. At 7 weeks of age, duct development in the mammary gland was markedly delayed in the LP group. No significant differences in the extent of ductal development were noted between the HP and NP groups. Morphologic development into terminal end buds, alveolar buds, lobules, and terminal ducts was determined for each diet group at 7 weeks and at sexual maturity plus 3 weeks (SM+3) of age. At 7 weeks, the terminal end bud was the dominant structure in the LP group and was significantly greater in number than in the HP and NP groups. The latter groups were dominated by the alveolar bud structures. At SM+3, the number of terminal end buds decreased, and the alveolar buds increased in the LP group; however, the numbers were still significantly different than in the HP and NP groups. This study indicates that dietary protein affects mammary duct proliferation and morphologic development.

Respiratory distress syndrome in immature lambs. Prevention through antenatal accelerated conditioning of the lung

We tested the effectiveness of constant distending pressure applied to immature lungs in preventing respiratory distress syndrome. Fetal lambs of 131 to 134 days gestation were delivered by cesarean section, but the umbilical circulation was kept intact for CO2 removal through the natural in situ placenta. The lungs were inflated to a pressure of 35 cm H2O (Group I, 11 animals) or 25 cm H2O (Group II, 14 animals), after which the airway pressure was maintained at 15 cm H2O through apneic oxygenation until total static compliance exceeded 0.5 ml (cm H2O)- 1kg -1. After a mean of 1.1 and 5.7 h, respectively, the animals were delivered and were given mechanical ventilation for 24 h. Twenty-four animals reached this aimed-for compliance and survived the period of mechanical ventilation in excellent health. A control group of fetal lambs was delivered immediately and treated with mechanical ventilation. Three of 10 control animals developed severe respiratory distress syndrome and died; 1 additional animal survived but with central nervous system involvement from severe hypoxia. We conclude that pulmonary inflation to 35 cm H2O pressure, followed by a constant distending pressure of 15 cm H2O, held until compliance reaches 0.5 ml (cm H2O)- 1kg -1, is an important element in the prevention of respiratory distress syndrome.