Maximum possible impact of tocolytics in preventing preterm birth: a retrospective assessment.

Although tocolytic drugs are widely used to try to stop preterm labor, their actual contribution to preventing preterm deliveries is unknown. Since tocolytic drugs are not used at the University of Manitoba, it was possible to estimate the proportion of preterm deliveries that might have been eligible for tocolytic drug therapy. Of 364 consecutive preterm deliveries between 24 and 35 weeks, only 9% would have been eligible for, let alone prevented by, tocolytic drug therapy, and even a smaller percentage of babies would actually have benefitted from their use. The use of tocolytic drugs can, at best, benefit only a very small percentage of babies born preterm. Whether the risks of treatment justify this small benefit is arguable.


Prenatal presentation of congenital chloride diarrhea: clinical report and review of the literature.

A case of congenital chloride diarrhea was diagnosed after delivery in a patient whose antenatal course was notable for massively dilated small and large bowel and persistent, severe hydramnios refractory to therapy. The pathophysiologic mechanism is a dysfunctional chloride-bicarbonate exchange in the brush border of the ileum. Antenatal presentation, prenatal diagnosis, and a review of the current literature are discussed.


Prenatal determination of demographic and attitudinal factors regarding feeding practice in an indigent population.

Demographic and attitudinal factors influencing the decision to breast- or bottle-feed were evaluated early in pregnancy by survey of 307 women in a low-risk prenatal obstetric clinic at a publicly funded hospital in Houston, Texas. Subjects responded to 17 demographic and 24 attitudinal questions. Racial classification revealed blacks 36.4%, whites 29.2%, and hispanics 30.8%. Twenty-five percent of the completed surveys were in Spanish. Of the total sample, 26.7% planned to breast-feed, 48.2% planned to bottle-feed, and 25.1% planned to do both. Multiple logistic regression analysis revealed six prominent independent risk factors for bottle-feeding. The most significant variable was lack of support for breast-feeding from a significant other (husband, mother, other relative, or friend), which had a odds ratio (OR) of 456.3. Other attitudinal variables achieving independent significance were disagreement with the statements "breastfeeding protects against disease" (OR = 4.0), "breasts were made for breastfeeding" (OR = 8.0), and "I want to know more about breastfeeding" (OR = 120.0). Significant demographic variables identified were completion of less than 12th grade (OR = 32.1), and age less than 35 years (OR = 43.3). These findings indicate the influence of significant others in the decision to breast-feed and suggest that future educational programs should require their inclusion if the prevalence of breast-feeding in this population is to be increased.


Surface tension of therapeutic surfactants (exosurf neonatal, infasurf, and survanta) as evaluated by standard methods and criteria.

Three commercial preparations for the treatment of neonatal respiratory distress syndrome (NRDS), Exosurf Neonatal (EX), Infasurf (IN), and Survanta (SU), were studied at 37 degrees C in both a pulsating bubble surfactometer and a vertical film surface balance. "Static" characteristics of adsorbed films were assessed with "bubble" at maximum radius (Rmax) and at minimum radius (Rmin). Adsorption time was time to stable film formation (gamma equilibrium). In dynamic experiments, the bubble was cycled (compressed-decompressed) between Rmax and Rmin at 20, 40, and 80 cpm. Spread films were cycled in the surface balance between maximum area (Amax) and minimum area (A(min)) at 1.5 cpm. In all experiments, maximum surface tension (gamma max) coincided with Rmax or Amax and gamma min with Rmin or A(min). All trials were continued until gamma max and gamma min were reproducible. Data were evaluated according to standard criteria for normal function both in vivo and in vitro of lipid mixtures (EX) or natural surfactants (IN, SU) prepared for treatment of NRDS. All preparations failed two of the four criteria, adsorption in the time of a deep breath and maintenance of stable, low gamma. Adsorption required 10 to 20 seconds and stable gamma was achieved only at equilibrium gamma, > 17 mN/m. IN and SU conformed in general to two criteria, gamma approaching zero on compression and low surface compressibility (< 0.09 m/mN), whereas spontaneously formed films of EX did not. EX was idiosyncratic in that these two criteria were met only after an apparent change of film conformation had been effected, possibly related to elimination of preparation additives from the surface.(ABSTRACT TRUNCATED AT 250 WORDS)


Hypothalamic-pituitary-adrenal axis function in premature neonates after extensive prenatal treatment with betamethasone: a case history.

Tests of hypothalamic-pituitary-adrenal axis function were performed on a set of 32-weeks' gestation triplets whose mother received 16 injections of betamethasone over 8 weeks prior to delivery to induce fetal lung maturation. The purpose of these studies was to determine if clinically significant suppression of fetal adrenocortical function occurred as a result of this repeated and prolonged prenatal exposure to glucocorticoids. Serum cortisol levels were measured on cord blood from each patient. Morning serum cortisol and 11-deoxycortisol levels were measured before and after an oral dose of metyrapone given at midnight on day 5. All three infants were clinically well at birth and had no evidence of hyaline membrane disease. Cord blood cortisol levels were low in each infant (1.97 +/- 0.25 micrograms/dl). By day 5, morning cortisol levels had become normal for each infant (10.77 +/- 2.42 micrograms/dl). Following the metyrapone dose, the 11-deoxycortisol levels rose 10- to 20-fold for each infant, indicating normal function of the hypothalamic-pituitary-adrenal axis by day 6. Adrenocortical suppression following multiple courses of prenatal betamethasone appears to be similar in degree and duration to that reported following brief antenatal therapy with this medication. Further studies are needed to confirm these anecdotal observations.


Group B streptococcal colonization in the diabetic gravida patient.

Previous reports have suggested that pregnant diabetic patients have higher carriage rates of group B Streptococcus (GBS) than nondiabetic gravidas. In order to evaluate this in our population, we cultured the posterior pharynx, endocervix, vagina, and rectum of 101 diabetic pregnant women and 100 nondiabetic gravida patients. The colonization rate of GBS was higher in the diabetic population, 31.7%, than in the nondiabetic group 19.0%, (p < 0.039). The vagina was the site most often positive in both diabetic and nondiabetic populations (23.8% and 17.0%, respectively, p = NS). The second site to culture positive overall and the only individual site that was positive significantly more often in diabetics was the rectum (16.9% versus 7.0%, p < 0.05). Differences in colonization rates were not evident when insulin requirement and diabetic classes were considered.


Prophylactic and emergent arterial catheterization for selective embolization in obstetric hemorrhage.

Treatment of obstetric hemorrhage by the selective embolization of damaged pelvic vessels under fluoroscopy holds promise as an alternative to surgical intervention. Unfortunately, the effectiveness of selective embolization is often compromised by its use in emergent settings following the failure of primary operative approaches. Therefore we compared the efficacy of prophylactic versus emergent catheter placement for selective embolization in nine patients with or at risk for obstetric hemorrhage. In four patients with acute obstetric hemorrhage catheterization and embolization was carried out following the failure of initial medical and surgical approaches. In five patients determined to be at risk for intrapartum hemorrhage based on sonographic findings, catheters were inserted into the hypogastric vessels prior to elective cesarean delivery. Three of these five patients subsequently required selective embolization. In comparison to patients undergoing selective embolization following prophylactic catheter placement, patients in the emergent group all had a coagulopathy at the time of embolization, sustained substantially greater blood loss, and had an increased rate of postpartum complications. Finally, there was a significant reduction in total embolization time and therefore in radiation exposure in patients undergoing prophylactic catheter placement prior to selective embolization. These data support the conclusion that in patients determined to be at risk for intrapartum or postpartum hemorrhage the prophylactic placement of catheters allows for selective embolization in a hemodynamically intact patient with stable coagulation indices, theoretically reducing the risk of maternal morbidity and possibly mortality.


Hemodynamic effects of combining epinephrine with nitroglycerin or nitroprusside during group B streptococcal sepsis in piglets.

Septic shock in young children is often characterized by clinical findings consistent with a reduction in cardiac index (CI) and elevation of systemic vascular resistance index (SVRI). In this context, infusion of inotropic agents, alone or in combination with vasodilators, has been recommended. We have utilized group B streptococcal (GBS) infusion in piglets to develop a model of low-CI/high-SVRI septic shock, and report here the effects of the combination of epinephrine (EPI) plus either nitroglycerin (NG) or nitroprusside (NP) in this model of infant sepsis. Piglets were anesthetized, intubated, and ventilated. All piglets received GBS continuously for 90 minutes and were further divided into three experimental groups. Group 1 received NG 16 micrograms/kg.min plus EPI 2 micrograms/kg.min; group 2 received NP 10 micrograms/kg.min plus EPI 2 micrograms/kg.min, and group 3 received 0.9% sodium chloride (saline) only. CI, which fell for all three groups at the onset of GBS infusion, rose significantly in group 2 animals (but not in groups 1 and 3). This effect was mediated entirely by an increase in myocardial stroke volume. Aortic blood pressure, initially unaffected by GBS infusion, rose significantly in both group 1 and 2 compared with group 3. SVRI, which rose for all three groups at the onset of GBS infusion, was further markedly elevated in group 1 (but not in groups 2 and 3). Pulmonary artery pressure and pulmonary vascular resistance index, both significantly increased after GBS infusion, were reduced in group 2 but not groups 1 and 3. These observations illustrate the potential for unexpected, and possibly detrimental, hemodynamic consequences when vasoactive agents are combined in young septic animals.(ABSTRACT TRUNCATED AT 250 WORDS)


Developmental aspects of percutaneous caffeine absorption in premature infants.

Caffeine is commonly used in the treatment of apnea of prematurity. The skin of preterm infants varies considerably in its level of maturity. To understand skin absorption in low birthweight infants (less than 1500 gm) with gestational age between 26 and 34 weeks, a group of 56 preterm babies was studied after percutaneous application of 7.5 mg twice daily of caffeine for babies with birthweight less than 1000 gm and 10 mg twice daily for babies with birthweight more than 1000 gm. The reported technique is a useful alternative method of drug administration in premature babies. This study indicates an inverse relationship between gestational age and skin absorption contributing to a better understanding of skin barrier function in the newborn.


Ultrasound diagnosis of immature cervical teratoma: a case report.

We report a case of cervical teratoma in a term female infant born to a 20-year-old white woman. There are rare tumors in neonates, occurring in approximately 1 in 20,000 to 1 in 40,000 live births. These tumors are accurately defined by ultrasound. Although benign, cervical teratomas cause respiratory compromise. In this case the tumor was removed surgically with no recurrence at the 10-month follow-up.


Neonatal alloimmune thrombocytopenia after maternal immunization with paternal mononuclear cells: successful treatment with intravenous gamma globulin.

We report a case of neonatal alloimmune thrombocytopenia and intracranial hemorrhage in an infant whose mother received immunizations of paternal mononuclear cells. This therapy is designed to prevent unexplained first trimester miscarriages. No previous cases of platelet autoimmunization associated with maternal immunization with paternal mononuclear cells has been reported. Treatment with antenatal maternal infusions of intravenous gamma globulin (IVGG) did not prevent fetal thrombocytopenia, but IVGG may become the treatment of choice for postnatal, antibody-mediated thrombocytopenia of the newborn.


Detection of intra-amniotic infection by gas-liquid chromatography.

The use of gas-liquid chromatography to detect short-chain organic acids in the amniotic fluid of patients with amnionitis has been previously described. Most of the studies describe patients in the early third trimester with such infections. The purpose of the current study was to confirm the correlation of infection with increased production of organic acids and to assess the effect of gestational age on the presence of these short-chain fatty acids in the amniotic fluid. Six patients with confirmed chorioamnionitis were used as positive control subjects. Seventy-two patients at various gestational ages from 18 to 42 weeks with negative Gram's stain and culture results from the amniotic fluid were used as negative control subjects. The data revealed an increased production of organic acids, particularly pyruvic, oxalic and succinic, in patients with amnionitis regardless of gestational age. Interestingly, patients with noninfected amniotic fluid also revealed an increase in the concentrations of volatile organic acids between 27 and 32 weeks' gestation. It appears from this study that previous results correlating chorioamnionitis with an increased production of organic acids in the amniotic fluid may have been confounded by gestational age.


Sonographic fetal growth curves from an indigent population in Atlanta, Georgia: I. Singleton pregnancies.

The sonographic estimation of gestational age relies on standards of normal fetal growth established in highly selective patient populations. The majority have used middle-class, Caucasian gravidas with excellent menstrual dating criteria. These reference populations differ considerably from the indigent patient population in most southern medical centers: menstrual dating is often imprecise and there is a high rate of low birthweight infants delivered. Therefore, we established models of fetal growth in a southern, indigent, predominantly black patient population. We also compare our study to other sonographic studies.


Creatine kinase and creatine kinase isoenzymes as a marker of uterine activity.

Creatine kinase (CK) and CK isoenzymes are known to fluctuate in labor. Reliable information about the longitudinal changes of CK and CK isoenzymes during labor is sparse. Nevertheless, they have been used to direct care in women with cardiopulmonary disease and preterm labor requiring tocolysis. This study evaluated fluctuations of CK and its isoenzymes longitudinally across labor in 49 women. Blood samples were obtained at 33 to 34 weeks' estimated gestational age, on admission in labor at 3 cm or less dilation, 8 cm to complete dilation, and postpartum in the recovery room. Specimens were analyzed for total CK, CK-MM, CK-MB, and CK-BB activity. CK levels increased for all peripartum patients (p < 0.001). CK activity at 3 cm was greater than at 34 weeks (p < 0.01). Furthermore, the early rise in CK activity was greater in those in active labor compared with those who required oxytocin stimulation (p < 0.001). CK values at 8 cm and postdelivery (mean IU/liter) were often above nonpregnant norms. The early rise of CK in spontaneously laboring patients versus those requiring oxytocin augmentation may represent a difference in uterine activity. Nonpregnant normative data for CK is not appropriate when assessing cardiovascular side effects of betamimetic therapy.


Hemodynamics associated with the diagnosis and treatment of pheochromocytoma in pregnancy.

A pregnant woman with an undiagnosed pheochromocytoma is described. Her presentation at 29 weeks' gestation was consistent with preeclampsia. Noninvasive measurement of cardiac output and ambulatory monitoring of blood pressure provided data that facilitated making the appropriate diagnosis and managing the patient until delivery at term.


Effect of magnesium sulfate on the vascular actions of norepinephrine and angiotensin II.

Magnesium sulfate is used for seizure prophylaxis in patients with preeclampsia. It also has significant effects on calcium metabolism and could, therefore, alter the pressor response to calcium-dependent vasoconstrictors. The present in vivo rat study examined the effect of magnesium sulfate to alter the pressor response to norepinephrine (NE) and angiotensin II (A II). Magnesium doses were chosen to approximate those used in treating preeclampsia. NE resulted in a significant rise in mean arterial pressure (delta MAP, 46 +/- 3.7 mmHg; p < 0.001). A II also resulted in a significant rise in MAP (delta MAP, 23 +/- 3.6 mmHg, p < 0.02). Magnesium sulfate alone had no significant effect on MAP but attenuated the pressor response to both NE (delta MAP, 16 +/- 1.5 mmHg) and A II (delta MAP, 12 +/- 2.5 mmHg). After discontinuation of the magnesium sulfate infusion, the control pressor responses to NE and A II were again seen (delta MAP, 39 +/- 3.5 mmHg and delta MAP, 28 +/- 4.2 mmHg, respectively). Although magnesium sulfate is not a primary antihypertensive agent, it may have effects on blood pressure by attenuating the actions of circulating vasoconstrictors.


Is there a "dominant twin" in utero?

A prospective study of 98 pairs of nonstress tests (NSTs) was obtained simultaneously from members of 30 twin gestations. Fifty-five percent of the total fetal heart rate (FHR) accelerations of both twins were associated with each other and occurred within 15 seconds of each other. There were 8.46% synchronous FHR accelerations of both twins, possibly reflecting evoked fetal movements. Statistical analysis failed to reveal evidence of a dominant twin in utero, with one twin initiating the majority of coinciding fetal movements with statistical significance in only three gestations. Examination of combinations of the 30 separate individual significance tests using techniques of meta-analysis demonstrated a p value of 0.81, indicating lack of dominance in any of the 30 pairs of twins. The probability plot, consistent with the large p value for the combination test statistic, suggested that fetal movements in two gestations are related, strengthening the hypothesis of in utero tactile communication between twins. We conclude that the existence of a "dominant twin" in utero cannot be detected by electronic FHR monitoring methods.


Surgical treatment of incompetent cervix.

A comparison of multiple factors in the surgical management of cervical incompetence was carried out in 114 procedures. Factors examined included training level of the operator, gestational age, cervical effacement and dilation at the time of operation, diagnostic evaluation, Shirodkar or McDonald procedure, year of the procedure, and tocolytic therapy. The endpoint for successful outcome was defined as 37 weeks or newborn weighing over 2500 gm rather than neonatal survival, thus differing from previous studies. All patients were delivered vaginally unless there was an obstetric indication for cesarean delivery. The most important determinants of a term birth in patients with incompetent cervix were operator experience and the use of a Shirodkar procedure.


Outcome of pregnancy in class A1 and A2 gestational diabetic patients delivered beyond 40 weeks' gestation.

The charts of all diabetic women and their infants delivered during the years 1983-1988 in our department were reviewed. The test group included consecutive gestational diabetic women class A1 (n = 65) and class A2 (n = 59), who delivered beyond 40 weeks of gestation. The mean gestational age at delivery was 40.90 weeks (range, 40.0 to 42.57) in class A1 and 40.49 weeks (range, 40.0 to 42.28) in class A2 patients. The first control group matched for age, parity, and presentation included 65 gestational diabetic patients class A1 and 59 A2 who delivered prior to 40 weeks' gestation. The second control group matched for age, parity, and presentation included 124 nondiabetic patients who delivered beyond 40 weeks of gestation (mean, 41.04 +/- 0.83 weeks). By allowing the pregnancies of gestational diabetic patients class A1 and class A2 to proceed beyond 40 weeks of gestation, we did not increase the incidence of perinatal mortality and morbidity rate. The cesarean section rate was low (10.76% in class A1 and 22.03% in class A2). We suggest that not only elective intervention prior to 40 weeks of gestation is to be avoided, but an attempt should be made to allow the gestational diabetics class A1 and class A2 to proceed to spontaneous labor.


[Control of breathing during exercise].

Although the control of breathing during exercise has been studied extensively that both neural and humoral factors may play a role in mediating the exercise hyperpnea, it remains unresolved whether the response is due solely to neural or humoral mechanisms and how the pulmonary gas exchange matches to the tissue exchange rates. At just onset of exercise ventilation can increase abruptly within 1 to 2 breathes (Phase I). Such a rapid increment of ventilation is not attributed to the humoral factor(s) due to the circulation delay from muscle metabolites. More rapid mechanism(s) such as irradiation from brain stream, afferent neurogenic control, blood flow increment as cardiodynamic theory might be considered. During moderate exercise intensity with a step function, ventilation increased exponentially to the steady state (phase II) after an abrupt increase at just onset of exercise. In this phase II, the breathing is controlled as to exchange the oxygen and carbon dioxide at rates appropriate for the acid-base homeostasis regulation. As a result, arterial blood gases and acid-base status must maintain within a narrow range despite of extremely enlarged metabolic rates by exercise. Some humoral factor(s) might be mediated for the control of breathing such as mean steady state error theory, arterial blood gases oscillation theory, feedback system by CO2, or optimization theory. At the heavy exercise intensity, anaerobic metabolism was supplemented to product for the enhanced energy requirement, so that ventilation increased non-linearly with oxygen uptake due to the lactoacidosis and its buffering activity. There has been a debate concerning cause and effect relationship between blood lactate increment and hyperpnea during exercise. Recently, arterial potassium concentration resulted from depolarization due to muscle contraction during exercise might stimulate to carotid bodies for increasing ventilation.


[Subcutaneous fat distribution in Japanese women. Part 1. Fat thickness of the trunk].

The thickness of subcutaneous fat were measured at 215 different points on the trunk in Japanese young women with using B-mode ultrasonic device. Subjects were 10 healthy Japanese females aged from 20 to 24 years. Average subcutaneous fat thickness over the trunk of 10 subjects was 9.8 mm, and it's standard deviation was 1.5 mm. Subcutaneous fat thickness showed the higher value at the buttock, the breasts and the abdomen and the lower value at the back. The difference of fat distribution between obese subjects and lean subjects was exhibited mainly on the abdominal parts but not on the chest and back parts of the trunk.


[Warming-up under cold environment].

Warming up procedures in the many antecedent reports, are almost under normal ambient temperature and they do not treat the warming up under low temperature. The purpose of this study was to investigate the effects of warming up by intensity and time in submaximal treadmill exercise (90% VO2max intensity during 10 minutes) on physiological parameters under cold environment in climate chamber (room temperature: 10 degrees C, relative humidity: 70%, wind velocity: under 0.2 m/sec). Eight trained collegiate basic skiers performed main exercise for 5 minutes after the following warming up conditions: NoW-up (no warming up), W50-15 (50% VO2max intensity 15 minutes), W70-15(70% VO2max intensity 15 minutes), W50-30(50% VO2max intensity 30 minutes) or W70-30(70% VO2max intensity 30 minutes). It was concluded that the most effective intensity and time of warming up in these conditions were 50% VO2max intensity and 30 minutes duration, that is, rather low intensity and longer duration time. It was suggested that a warming up with a high intensity and short duration was effectless under cold.


Effects of physical activity and life-style factors on uterine contraction frequency.

In this cohort study, uterine contractions were recorded in 81 low-risk pregnant women who wore ambulatory tocodynamometers continuously during three 72-hour periods at advancing gestational ages. During these periods, they also recorded their daily activities in a diary. Examination of the data, in general, revealed no association between uterine contraction frequency and habits such as smoking, alcohol consumption, or drinking caffeinated beverages. Physical activities, such as prolonged standing, heavy housework, lifting, or organized exercise also did not appear to affect uterine contraction rates. Only climbing stairs and walking were associated with increased contraction frequencies, but this effect, although statistically significant, was relatively small in magnitude and was present only during the last gestational age period monitored (30 to 33 weeks).


Optimum comfort limits determination through the characteristics of asymmetric thermal radiation in a heated floor space, "ondol".

This study was undertaken to evaluate the effects of the asymmetric radiation on thermal comfort, and to suggest the optimum comfort limits in a radiant heating space. The index of V.R.T. (Vector Radiant Temperature) was used to describe the environmental quality of the heated floor space. Optimum comfort limits of this space were suggested through both theoretical and empirical studies. It is recommended to use not only man's sensation of the ambient air but also that of the floor surface for the determination of the optimum comfort limits on the heated floor space such as an "Ondol" in Korea. In the present study the optimum comfort limits were suggested in terms of the V.R.T. The optimum limits obtained were as follows: the vector radiant temperature 11.0 approximately 15.0 K.


Influence of noise on heart rate and quantity of work in mental work.

In the present study, we investigated the correlation between the physiological function, heart rate (HR) and the quantity of work performed when A-weighted sound pressure level of factory noise or construction noise was varied during the mental operations of calculation and erosion. Furthermore, we looked for differences in the effects of sound noise and music on the quantity of work performed. The A-weighted sound pressure level was set at four levels of background noise, i.e. 60, 70 and 80 dB (A). The music sound level was set at 70 dB (A). The subjects were exposed to factory noise, construction noise and music during their mental work. A balanced factorial experiment was conducted with a total of 16 combinations of types of mental work (two levels of calculation and erosion), sound noise (two levels of factory and construction sound noise), and A-weighted sound pressure levels (four levels). The order of the experimental procedures was determined at random. The following conclusions were made from the findings of the study. 1) HR elevation occurred due to exposure to sound noise, and further increase in HR resulted from an increase in the A-weighted sound pressure level. This result can be attributed to the action of sound noise as a stressor, which excites sympathetic nerves, leading to an elevation of HR. 2) The quantity of work performed decreased with an increase in the A-weighted sound pressure level. 3) When the subjects were exposed to music with an A-weighted sound pressure level of 70 dB (A) instead of sound noise of the same level, almost no elevation of HR was observed. However, the quantity of work completed when exposed to music was less than that performed when exposed to sound noise of the same A-weighted sound pressure level.


The effect of color temperature of lighting sources on the autonomic nervous functions.

The present study was designed to investigate the effects of color temperature of lighting sources on the heart rate variability. Eight male students volunteered as subjects. The heart rate variability during task and rest sessions were estimated under nine different lighting environments consisting of three levels of color temperature (3000 degrees K, 5000 degrees K and 6700 degrees K) and three levels of illuminance (1001x, 3001x and 9001x). The lighting condition caused no effect on the mean heart rate. On the other hand, the power spectrum of heart rate was significantly influenced by the lighting conditions. The respiratory sinus arrhythmia component and Mayer wave related sinus arrhythmia component of the power spectrum increased under higher color temperature conditions. Judging from the consistency of heart rate level, the balance between the effects of parasympathetic and sympathetic nervous systems remained at a constant level irrespective of lighting quality and intensity. Therefore, both parasympathetic and sympathetic nervous functions were concluded to be enhanced under higher color temperature conditions. The light with higher color temperature was considered to activate the autonomic nervous function more than the light of lower color temperature. The effect of color temperature was much remarkable in the rest session comparing with the task session. This fact was discussed from the viewpoint of color temperature effect in environmental lighting.


[Estimation of energy expenditure and the validity of pitch counting during walking and jogging by piezoelectric materials].

The purpose of the present study was to assess the validity of Piezo-electric accelerometer for estimating energy expenditure in walking and jogging. Energy consumption by oxygen uptake was determined during steady state level of treadmill walking at the speed of 60, 80 and 100 m/min and jogging at the speed of 100, 120, 140, and 160 m/min for 10 subjects. There was a highly significant correlation between the energy consumption and the estimated energy expenditure by an accelerometer despite the attached position (r = 0.912 at the waist, r = 0.915 at the chest, P < 0.001), which suggests accurate estimating energy expenditure in the field.


The change of allergen-specific IgG subclass antibodies during immunotherapy in mite-sensitive asthmatic children.

Fifty-six Dermatophagoid farinae (D.f)-sensitive asthmatic children were hyposensitized by D.f-crude extract for two years. Serum total IgG subclass antibodies and D.f-specific IgE and IgG subclass antibodies were measured by ELISA before and after 2 years of treatment. The results showed that 1) After two years of treatment, there were significantly higher levels of total serum IgG1 in both responder and non-responder groups than those before treatment (p less than 0.01). The responder group also had significantly higher values of total IgG2 and IgG4 after immunotherapy (IT) (p less than 0.05), but not in the non-responder group. 2) The serum levels of D.f-specific IgG3 and IgG4 antibodies in responder group increased significantly after IT (p less than 0.05). On the contrary, the D.f-specific IgE and IgG1 IgG1 in the responder group were significantly lower than those before IT. No signi- in the responder group were significantly lower than those before IT. No signi-body titres before and after IT was found in non-responder group. 3) There was a significant correlation between the total IgG4 and D.f-specific IgG4 antibody (r = 0.634, p less than 0.01). The correlation coefficient was 0.634. No correlation was found between the other IgG subclass antibodies and D.f-specific IgG subclass antibodies. 4) Correlations between the levels of D.f-specific IgE and IgG subclass antibodies were highly significant both in IT-responder and non-responder groups. There was a significant correlation between the levels of D.f-specific IgG1 and IgG4 in non-responders, while no relationship was observed in the responder group.(ABSTRACT TRUNCATED AT 250 WORDS)


Antineoplastic effects of gallium nitrate on human medulloblastoma in vivo.

Gallium nitrate possesses antineoplastic activity against certain solid tumors and has been demonstrated to be an effective agent in reducing cell proliferation and DNA synthesis in the medulloblastoma Daoy cell line in vitro. In prior studies, gallium inhibited the cellular uptake of 59Fe by brain tumor cells; however, this block in 59Fe uptake was variable and closely paralleled the inhibitory effects of gallium on cell growth. In vivo trials now have been conducted and have yielded some promising results. Nude mice received intradermal injections of medulloblastoma Daoy and then allowed to grow tumors. When the mice had developed at least one tumor between 9 to 10 mm in diameter, a 10-day course of intraperitoneal gallium nitrate injections was initiated. Gallium nitrate treatment reduced overall tumor growth rate and reduced actual tumor size. Nephrotoxicity was severe, but may be preventable by continuous gallium infusion and use of diuretics and hyperhydration.


Antinuclear antibody detection using streptavidin-biotin-peroxidase complex on HEp-2 cell substrate.

The streptavidin-biotin-peroxidase complex (SABC) technique was compared to conventional indirect immunofluorescence (IIF) for the detection of anti-nuclear antibody (ANA) on HEp-2 cell substrate. SABC showed higher specificity and predictive value and gave more reproducible titres and clearer staining patterns than IIF in sera from a series of rheumatic disease patients. Sera from 80 patients with various types of rheumatic diseases and 20 without rheumatic disease were further tested using the SABC method. All systemic lupus erythematosus (SLE) sera were positive. The overall sensitivity was 95%, specificity 90% and predictive value 97% for rheumatic disease. The rim pattern was associated with SLE and mixed connective tissue disease. The nucleolar/homogeneous pattern was associated with scleroderma and SLE in remission. ANA titre and staining pattern have limited value in the clinical assessment of rheumatic disease; however, ANA has very high sensitivity for SLE and remains an excellent screening test.


The presence of specific IgE to salicyloyl and O-methylsalicyloyl in aspirin-sensitive patients.

Certain adverse reactions to aspirin (ASA), nonsteroidal anti-inflammatory drugs (NSAIDs) and pyrazoline derivatives resemble IgE-mediated hypersensitivity. However, convincing evidence of antigen-antibody interactions or of the inhibition of the cyclooxygenase pathway of arachidonic acid metabolism leading to an increase in the generation of leukotrienes (LTs) and a decrease in the generation of prostaglandins (PGs) was not fully demonstrated. In this study, two types of specific IgE antibodies have been found in 27 serum samples from 28 ASA-sensitive patients with salicyloyl-discs and O-methylsalicyloyl-discs by Radio Allergo Sorbent Tests (RAST). The positive rates were 96.4% and 71.4%, respectively. In contrast, no positive results could be found in 10 normal donors without ASA sensitivity after ingestion of ASA 500 mg/day for 14 days. Further investigation of the chemical structure of epitopes was done by cross inhibition studies. Our results are an increasing evidence in favour of an IgE-dependent mechanism in patients suffering from ASA sensitivity. Hopefully, the determination of specific IgE antibodies will be a safe diagnostic method of ASA sensitivity in vitro.


Neurologic outcome of propionic acidemia.

Twenty patients with propionic acidemia were reviewed retrospectively. Two groups were identified: those who presented in the first week of life (11 patients) or after the neonatal period (9 patients). The early onset of disease had a much higher death rate (hazard ratio: 7.52) and all patients in this group were mentally retarded (IQ < or = 60). Movement disorder was common in both groups. Of the early-onset group, 3 patients had mild chorea or dystonia. Four in the late-onset group had a severe movement disorder. In the late onset group, cranial computed tomography disclosed transient basal ganglia lucencies following an episode of metabolic decompensation; however, no disturbance in amine neurotransmitter metabolite concentrations were found in the cerebrospinal fluid.


Vigabatrin in intractable childhood epilepsy: a retrospective study.

The effects of vigabatrin were studied over a 6-month period in 43 patients with intractable epilepsy. Children with complex partial seizures, with or without secondary generalization, responded best with more than one-half achieving a greater than 50% reduction; generalized tonic-clonic seizures also improved but there was no significant change in absence or myoclonic seizures. Four patients are seizure-free on monotherapy with vigabatrin. The drug was well tolerated with few side effects.


A study on antigenic and allergenic changes during storage in three different biological extracts.

The stability of three allergens common in tropical countries was evaluated under different storage conditions. Prosopis juliflora (PJ), Rhizopus nigricans (RN), and wheat dust (WD), were taken as representatives of various groups of allergens viz, pollen, fungi and dust. The extracts were stored in buffer containing phenol (0.4%) or glycerol (50%) at temperatures ranging from 4-55 degrees C for 15 to 60 days. Protein content of PJ extract was reduced remarkably when it was stored at 40 degrees C for 45 days. Thin layer isoelectric focusing and rocket immunoelectrophoresis of PJ showed that certain antigenic proteins degrade rapidly even at 25 degrees C as early as day 15. However, two to three proteins of PJ remain stable at a higher temperature (40 degrees C) for two months. Relative radioallergosorbent test (RAST) inhibition showed substantial loss of allergenic activity in all the three extracts, when stored at higher temperatures (25-55 degrees C) even for short durations, i.e., 15 days. Extracts (PJ and RN) containing 50% glycerol were found to be stable, retaining more than 50% activity, even when stored at 55 degrees C for 40 days, while extracts without glycerol lost more than 75% of their allergenic activity. However, addition of glycerol did not change the stability of wheat dust allergenic extract. The present findings indicate that allergenic extracts behave differently when stored. Hence, the stability of each extract should be determined individually.


Dot-blot ELISA for the detection of IgM RF and IgA RF.

Dot-blot ELISA was developed for the detection of IgM RF and IgA RF. Normal rabbit IgG (NRIgG), concentration 100 micrograms/ml, was used as the antigen for dotting on the 0.45 microns pore size nitrocellulose membrane. Serum, conjugate and substrate incubation conditions were at room temperature for 1 hour, 1 hour and 3 minutes, respectively. The membrane with NRIgG dot could be sotred for 6 weeks before use in the assay. Positive results of IgM RF, at the serum dilution 1:800, were found in 31/51 patients with either classical or definite rheumatoid arthritis and 3/68 normal healthy individuals. Positive IgA RF, at the serum dilution 1:100, was found in 27/51 of the former and none of the latter. Significant concordance with high agreement index was found between the results of the dot-blot ELISA developed and those obtained from ELISA performed in microtitre plate (Kappa greater than or equal to 0.78 for IgM RF and 0.83 for IgA RF, p less than 0.001).


Re-evaluation of ELISA and latex agglutination test for rheumatoid factor detection in the diagnosis of rheumatoid arthritis.

An indirect ELISA for the determination of each isotype (IgM, IgG, IgA, IgD, IgE) of rheumatoid factors (RF) was performed with sera obtained from 77 patients with either classical or definite rheumatoid arthritis (RA) and 319 controls, using rabbit IgG as the antigen. The results were compared with those of a commercial latex agglutination test, using denatured human gamma globulin as the antigen for rheumatoid factor determination. At the cut-off level at which positive results were found in less than 5% of normal controls, ELISA for IgM RF determination had sensitivity, specificity, efficiency, positive predictive value and negative predictive value of 46.75%, 98.12%, 88.13%, 85.71%, 88.41%, while those for IgA RF were 46.75%, 93.42%, 84.34%, 63.16%, 87.91% and for IgG RF were 59.74%, 92.16%, 85.86%, 64.78%, 90.46%, respectively. These indices by latex agglutination test were 83.11%, 93.73%, 91.67%, 76.19% and 95.83%, respectively. IgD RF titre greater than or equal to 1:5 was detected in 19/77 RA patients and 4/200 normal controls while IgE RF titre greater than or equal to 1:5 was detected only in 7/77 RA patients. Thus, ELISA did not appear to have any advantage over latex agglutination test for diagnosis of RA.


Sinusitis in Thai asthmatic children.

The radiographic appearance of sinuses was studied in 146 Thai asthmatic patients aged 1-13 years. Forty-eight percent of cases showed sinusitis by the radiographic criteria. The maxillary sinus was most commonly involved (98.6%). Thirty-three percent had ethmoidal sinusitis and 7% of those with developed frontal sinuses had frontal sinusitis. Thirty-three percent had more than one sinus involved. Those with frontal sinusitis always had maxillary and/or ethmoidal involvement. Sixteen cases had signs and symptoms of sinusitis and all of the cases had the radiographic appearance of sinusitis. There was no correlation between the occurrence of sinusitis and duration or severity of asthma. There was no difference in the occurrence of sinusitis between those with or without allergic rhinitis. No correlation between severity of sinusitis and age of patients was observed.


ELISA for seroepidemiological study of exposure to Vibrio cholerae of population in Krabi Province, Thailand.

Seroepidemiological study of Vibrio cholerae exposure was carried out in Krabi Province during January 1989 to December 1990 using indirect ELISA to determine serum antibodies to lipopolysaccharides (LPS) of V. cholerae. Among 363 serum samples obtained from cord blood and venous blood of healthy persons, aged from 6 months to over 50 years, 65% and 64% were found positive for specific IgG and IgM against LPS of V. cholerae, respectively. The seroprevalence of V. cholerae infection increased with age from that found at 6 months, being highest in the age groups of 30-49 years for IgG and 15-29 years for IgM. The seroprevalence of V. cholerae infection was higher among female Muslims and home-makers, and increased with the family income. The seroprevalence of cholera infection was also influenced by home location, methods of food storage and water supply. These data suggested that a large number of Krabi's population had V. cholerae infection.


Comparison of immunogenicity of hepatitis B vaccine between low and normal birth weight infants.

A comparative study was conducted to evaluate the immunogenicity of hepatitis B vaccine in low and normal birth weight infants. Hepatitis B vaccine (Hevac B Pasteur) was given to 50 low birth weight infants and 50 controls, matched by sex and date of delivery. The vaccine was given at birth, 1, 2 and 12 months of age. HBsAg and anti-HBs were assessed at birth, 4, 9 and 13 months of age by the micro-ELISA technique. Using the geometric mean titre of anti-HBs and the seroconversion rate as indicators, the immunogenicity of hepatitis B vaccine in low birth weight infants was as good as in normal birth weight infants.


Status and trend of HIV-1 infection and AIDS in Taiwan, December, 1991.

From May 1, 1985 to December 31, 1991, a total of 4,962,707 serum samples from 8 population groups in Taiwan were tested for anti-human immunodeficiency virus type 1 (anti-HIV-1). In total, 256 samples were seropositive; of these individuals, 43 developed acquired immunodeficiency syndrome (AIDS): 29 were homosexuals; 5 were hemophiliacs; 8 were heterosexuals and 1 was of unknown risk. Although the prevalence of HIV-1 infection and AIDS remains low compared with other countries, since 1988 the increase has been rapid. Before 1977 the majority were homosexuals and hemophiliacs; thereafter the risk groups diversified, with a trend away from homosexuals and hemophiliacs towards heterosexuals and intravenous drug abusers (IVDAs). A few patients have caused serious social problems for the public, health care workers and families. Active community efforts are needed to achieve future success in the control of HIV-1 infection and AIDS in Taiwan.


Analysis of antibody levels before and after praziquantel treatment in human paragonimiasis heterotremus.

Enzyme immunoassays (ELISA) and Western blot analysis were used to determine IgG antibody levels in patients infected with Paragonimus heterotremus from Thailand before and after treatment with praziquantel. An IgG antibody ELISA showed that a substantial reduction of antibody levels occurred after one year of treatment. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis showed that P. heterotremus adult extract is highly complex, consisting of more than 9 antigenic bands with molecular size ranging from 123 kDa to less than 12.3 kDa. Two prominent bands of 31.5 kDa and 18.5 kDa were found to show consistent reactions with all serum samples from the pretreatment group. There was a marked reduction in the intensity of the reaction of the 31.5 kDa band with each serum sample from post-treatment patients but the other bands disappeared during the one year interval.


Transcutaneous gas tensions in the sacrum during the acute phase of spinal cord injury.

The first few months following injury to the spinal cord requires constant care of the subject if tissue breakdown is to be avoided. The management of acute traumatic cases involves complete bedrest in a supine position with appropriately positioned pillows to minimize trauma to the bone prominences. This study assesses the effectiveness of the management procedure in terms of the tissue response at the sacrum of 15 acute spinal cord injured subjects. The measurement of mean interface pressures during a representative period of recumbency was performed and these were related to changes in transcutaneous gas tensions (TcPO2 and TcPCO2), which are reliable indices of tissue viability. A series of six variables was established which were compared to each other using non-parametric statistical analyses. It was shown that this group of subjects demonstrated a normal mechanism whereby the level of carbon dioxide was able to control the local vascular tone. The results also suggested that the practice of gapping at the sacrum should be revised to reduce mean sacral pressures and minimize the possibility of tissue breakdown, the risk of which is constant throughout the first three months following injury.


Reconstruction of the anterior cruciate ligament.

Ligaments are strong collagenous structures that act as constraints on joint motion, thus confining the articular surfaces to more or less the same paths. In so doing they prevent arbitrary apposition of these surfaces from occurring and resulting in abnormal stresses which may damage the joint surfaces. Ligaments rupture due to excessive loads, particularly those resulting from trauma occurring during sporting events or motor vehicle accidents. Knee and ankle joints have the highest frequency of ligamentous injuries. This paper is a brief review of the current approaches to the reconstruction of the knee ligaments with specific reference to the anterior cruciate ligament (ACL) being the most frequently reconstructed. This is not only because it is frequently injured but also because of the debilitating consequences of such an injury. Approaches ranging from the conservative to those that advocate the use of frank prosthetic replacement have been adopted by surgeons at both ends of the spectrum. Following a discussion of the rationale for reconstruction of the ACL, the mechanical and biological considerations of the reconstructive procedure are discussed. The different methods of ACL reconstruction are reviewed. These include: (a) primary repair, (b) reconstruction with different tissues, including autogenous allografts and xenografts, (c) reconstruction employing different synthetic devices. A brief discussion of the procedures used for reconstruction with different types of tissue and of the surviving examples of the synthetic devices will follow.


A comparison of various loading configurations of the proximal femur for the evaluation of reconstructive surgical procedures.

The study was designed to evaluate the effect of different loading configurations on stem and bone stresses in simulated total hip arthroplasty. The traditional experiment design of loading the model through the head of the prosthesis by the resultant joint force was compared with a more realistic model which included an abductor strap to simulate the abductor muscle force. In addition, an alternative experiment design was evaluated in which a loading arm was clamped directly on to the head of the prosthesis. The results show that loading the model by the resultant joint force not only changes the magnitude of the stresses but also the stress distribution compared to the abductor muscle model. The new experiment design closely approximates stresses seen in the abductor muscle model below the lesser trochanter. In the proximal region, the stresses are increased on the medial side and decreased on the lateral side. The advantages of the proposed loading model are: (a) easy and reproducible set-up and alignment is facilitated, (b) different positions of the femur (flexion, extension) can be simulated and (c) a more realistic stress distribution and magnitude is achieved.


The function of bipolar hip prostheses--a laboratory study using cadaveric acetabula.

Cadaveric acetabula were mounted in a hip simulator and the friction developed in each during articulation with a series of metal femoral head prostheses of differing sizes was measured. In a separate study, assembled Hastings bipolar hip prostheses were subjected to weight-bearing forces in the same acetabula and their self-righting mechanism was observed. The self-righting mechanism was found to function efficiently, in most cases overcoming the combined friction of the inner and outer articulations of the Hastings hip. However, during motion in the hip simulator a wide variation of friction was observed between different acetabula and within the same acetabulum with differing head size. In several cases this acetabular friction was found to be less than the friction in the inner articulation of the Hastings bipolar hip prosthesis, and this may explain some cases of reported failure of biarticular function.


The CADCAM contribution to customized orthopaedic implants.

CADCAM (computer aided design/manufacture) production methods are often associated with mass production; working in the medical field at the Department of Biomedical Engineering, the requirement is for one-off, individualized implants. Using a knowledge-based system, implant designs are produced from X-ray data. Assembly from modular components has greatly reduced the production time of implants for bone tumour cases. CADCAM techniques are also used in the production of custom-made hip replacements using digitized data gathered from radiographs. Femoral canal shape is calculated and the optimal implant designed and manufactured from titanium alloy on the Department's CNC (computer numerically controlled) machines.


Revision of cemented fixation and cement-bone interface strength.

Interfacial shear strength between poly(methyl methacrylate) (PMMA) bone cement and cancellous bone was measured in bone samples from human proximal femora. Samples were prepared with fresh cement-bone, fresh cement inside a mantle of existing cement and with fresh cement-revised bone surfaces. Push-out tests to measure shear strength caused failure only at bone-cement interfaces; revised bone interfaces were 30 per cent weaker (P < 0.02) than primary interfaces. The clinical relevance is that revision of cemented joint arthroplasties may necessitate removal of components with sound cement-bone fixation. The practice of removing all traces of PMMA cement may not yield the optimal fixation; adhesion of fresh cement to freshly prepared surfaces of the existing cement might also be considered where circumstances are favourable.


A model of the geometrical changes in aortic valve leaflets in response to leaflet extension and variable boundary conditions.

The function, deformation and performance of heart valve leaflets are dependent on the material properties and the geometry of the leaflet. As the leaflet acts as a constrained membrane the geometry is dependent on the boundary condition applied to the leaflet and any permanent extension of the leaflet. Both of these factors are varied during the preparation of frame-mounted porcine bioprosthetic heart valves and surgical insertion of free-sewn valves. This can result in abnormal geometry and function. A mathematical model has been developed which describes these changes in geometry of a cylindrical leaflet as a function of the diameter of the aortic root (boundary conditions) and the length (or permanent extension) of the leaflet. Both the angle of inclination and the radius of curvature of the cylindrical leaflet were reduced with increased leaflet length or decreased aortic diameter. Agreement was found between the model predictions and experimental observations in porcine bioprosthetic heart valves, where abnormal leaflet geometries are produced by non-physiological boundary conditions and permanent set of the leaflets by fixation with glutaraldehyde. The general solutions developed in this model allow leaflet geometries to be predicted for a range of conditions in free-sewn and frame-mounted valves.


AIDS and arthroscopic surgery.

There are an estimated 8 to 10 million people worldwide infected with human immunodeficiency virus (HIV). The true extent of infection in the population is unknown, and many are unaware of their HIV status. Arthroscopic and arthroscopically assisted surgery is less invasive and bloody than other orthopaedic procedures, and seemingly less hazardous to surgeons. Nevertheless, the potential for exposure exists. Arthroscopic surgeons routinely experience gown, face-mask and shoe-cover saturation from the splashing of blood-tainted irrigation fluid. Glove perforations by needles, sharps, and bone fragments can occur. Bone and tissue allografts pose risks to both surgeon and patient, as HIV has been recovered from fresh, frozen and freeze-dried specimens. The process of cleaning and disinfecting arthroscopes adequately can damage these expensive devices. This article addresses the safeguards that arthroscopic surgeons should take to prevent exposure to HIV. Effective sterilizing and disinfecting techniques for arthroscopes are also discussed.


Arthroscopic microdiscectomy.

Follow-up examinations performed a minimum of 2 years postoperatively showed that no neurovascular complications developed in 100 patients who underwent arthroscopic microdiscectomy for treatment of herniated discs at L3-4, L4-5, or L5-S1. By using a posterolateral approach, endoscopic control, and specially designed straight, upbiting, and deflectable forceps, it was possible to remove not only fragments located in the center of the nucleus, but also fragments that had migrated posteriorly and posterolaterally. Analysis of operative results by a modification of the Rush-Presbyterian-St. Luke's lumbar spine analysis system demonstrated that 88 of the patients attained excellent or good results and 12 attained poor or fair results. The outcome of surgery was not related to age, sex, or surgical level. The most common causes of an unsuccessful surgical outcome were lateral recess stenosis and sequestered fragments missed in the preoperative work-up.


Arthroscopic therapy of recurrent anterior luxation of the shoulder by capsular repair.

Sixty-five cases of recurrent anterior unidirectional dislocation of the shoulder were treated by arthroscopic capsular repair. In this approach, the arthroscope is inserted through a posterior portal. Using mostly an anterior portal, a 5-mm hole is drilled across the neck of the glenoid, between the 3 and 4 o'clock positions. A 5-mm working cannula is passed from the posterior portal into the joint. Mostly through the anterior portal, four to six retention U-sutures are placed in the labrum, the middle and inferior glenohumeral ligament, and the subscapularis tendon. A 25-cm-long, 2.0-mm K-wire with an eye is used. The sutures are pulled out posteriorly through the cannula and tied on the fascia of the infraspinatus muscle. The goal of the procedure is to reattach the detached labrum-ligament complex (LLC) and achieve a capsulorrhaphy in a medial-lateral and superior-inferior direction. There were nine redislocations during a follow-up period of 24-60 months (average, 35.3 months). Reasons for redislocation were (a) fewer than four sutures; (b) no sutures of the LLC; (c) placement of the drill hole in the top third of the glenoid; (d) nontraumatic dislocation; (e) no Bankart or Hill-Sachs lesion; (f) transverse tear of the LLC; or (g) technical errors. Redislocation was more common in male patients.


Effusions after anterior cruciate ligament reconstruction using the ligament augmentation device.

Persistent effusions occurred in 4.3% (seven patients) of 164 patients who underwent anterior cruciate ligament (ACL) reconstruction using an autograft augmented with the ligament augmentation device (LAD) between 1986 and 1989. No bacteria were cultured from the joint fluid. The radiograph in each case showed a tibial drill hole located anteriorly or anterolaterally. Arthroscopy confirmed an abraded LAD in six cases and breakage of the LAD in one case and impingement of the graft on the femoral condyle during extension. Under polarized light microscopy, the histology of the synovia showed foreign body giant cells in one case and particles among the proliferative cells in four cases. The effusions subsided in two cases after notchplasty and in five cases after removal of the LAD. Impingement of the graft on the femoral condyle due to incorrect positioning of the tibial drill hole presumably produced particles that induced synovitis and effusions.


Videoarthroscopy: review and state of the art.

Since the introduction of videoarthroscopy, there has been rapid technological advancement. The charged couple device (CCD) has become the standard small pickup unit for the present cameras. The video signal processing and transfer has been modified and improved. New Y/C or super VHS and red, green, blue (RGB) systems have been associated with improvements in monitors, video recorders, and video printers. Measurements of video quality such as resolution, signal-to-noise ratio, pixels, and contrast have been confusing to clinicians evaluating these new systems. Equipment compatibility and the weak-link theory is important to understand when selecting new equipment. This review article presents an update for the clinician who wants more information to differentiate among the new video arthroscopic systems.


Office arthroscopy: a diagnostic alternative.

Twenty patients with enigmatic knee symptoms were selected for evaluation by both magnetic resonance imaging (MRI) and office arthroscopy. Office arthroscopy was performed in a standard examination room using a miniature (1.7 mm) fiberoptic arthroscope under local anesthesia. All MRI scans were performed on a state-of-the-art 1.5-T magnet unit, and included specialized cartilage sequences in 7 patients. In 14 patients, 26 areas showed articular cartilage changes by arthroscopy (grade 2-3). Only nine of these areas were detected by MRI (sensitivity 34.6%). There were five false-positive and four false-negative readings of meniscal tears by MRI as compared with office arthroscopy. These results improved when postoperative menisci were excluded. Only one of three anterior cruciate ligament (ACL) disruptions identified by MRI could be verified by arthroscopy. The one posterior cruciate ligament (PCL) disruption was confirmed by both techniques. MRI was superior to arthroscopy in identifying bone contusions, subchondral sclerosis, and medial cruciate ligament (MCL) sprains. Office arthroscopy is an accurate and cost-efficient alternative to MRI in diagnostic evaluation of knee pathology in patients with enigmatic symptomatology.


Preoperative computed tomography scanning and arthroscopy in predicting outcome after lateral retinacular release.

We initiated a study to look at preoperative, flexed-knee, midpatellar computed tomography (CT) scans and intraoperative arthroscopic findings of lateral patellar articular degeneration in predicting the results after lateral retinacular release for failed nonoperative treatment of anterior knee pain. Twenty patients with 30 painful knees underwent preoperative flexed-knee, midpatellar CT scans that were retrospectively classified by the method of Fulkerson into normal alignment, lateral subluxation, lateral patellar tilt, and combined tilt and subluxation. Arthroscopy was performed before open lateral release. The lateral facet of the patella was graded as either minimal changes (Outerbridge I or II) or advanced (Outerbridge III or IV) changes. Patients were followed for a minimum of 2 years and graded on a standard patellofemoral rating scale. Only 22 of 30 knees that were thought to be clinically malaligned, actually were malaligned by CT scan; eight CT scans were interpreted as normal. The results were further stratified into group A (CT-documented tilt, minimal facet changes), group B (CT-documented tilt, advanced facet changes), and group C (normal CT). Ninety-two percent of group A were rated good or excellent. Twenty-two percent of Group B rated good/excellent, 33% fair, 44% poor. Only 13% of group C rated good (one patient). Based on the results of the study, we recommend lateral release for anterior knee patients with CT-proven patellar tilt who have not responded to conservative treatment and have minimal facet changes with minimal or no subluxation. Lateral retinacular release should not be offered as a treatment to the patient with a normally aligned patella because poor results will most likely result.


Medial patellofemoral ligament reconstruction for recurrent dislocation of the patella: a preliminary report.

We present a surgical technique for the treatment of recurring dislocation of the patella. The procedure, based on Galleazzi's tenodesis of the semitendinosus, uses minimal dissection and small incisions to improve cosmetic results and speed recovery. A polyester ligament is passed through a bone tunnel at the midline of the patella and fixed at the medial condyle, thus creating a medial patellofemoral neoligament. We have reviewed the results of 30 knees in 30 patients with an average follow-up of 39 months. Twenty-five patients (83.3%) showed significant improvement of their initial complaints.


Intraarticular pressures in a gravity-fed arthroscopy fluid delivery system.

Seven consecutive patients undergoing arthroscopic surgery in a gravity-fed fluid delivery system were studied. The average minimum adequate intraarticular pressure (MAIP) was 55 mm Hg. The height of a saline bag above the knee necessary to achieve this average MAIP was 75 cm. There was a positive correlation between diastolic blood pressure and the minimum adequate intraarticular pressure in this study. There was no positive correlation between systolic blood pressure and the MAIP.


Arthroscopic partial meniscectomy: a long-term follow-up.

A follow-up study was conducted to clarify the clinical and radiological long-term consequences of arthroscopic meniscus resection. One hundred thirty-six patients who had unilateral arthroscopic resection of an isolated meniscal tear attended for an interview and a physical and radiological examination. Follow-up averaged 8.5 years, with a range of 7.9-11.6 years. The reoperation rate was as high as 22.8%, but was the lowest in the bucket handle tear group (13%). Pain after exercise was less frequent among patients treated for a bucket handle tear compared to other lesions. Fifty-three percent of the patients had at least one of the Fairbanks change in the operated knee and only 22% in the control knees. The radiographic result was not influenced by the type of meniscus lesion nor were high age or intraoperatively described cartilage damage factors of significance. Malalignment less than 4 degrees of valgus and greater than 10 degrees of valgus was found to be a significant risk factor for the development of degenerative changes following meniscus resection.


Serial magnetic resonance study assessing the effects of impingement on the MR image of the patellar tendon graft.

This study was designed to serially analyze the magnetic resonance (MR) appearance of patella tendon grafts during the first year of implantation, and to determine if the sagittal location of the tibial tunnel affects the MR appearance of the graft. An additional goal was to analyze the effect of the sagittal placement of the tibial tunnel placement on knee extension and stability. Two groups were defined by comparing the sagittal relationship of the tibial tunnel to the slope of the intercondylar roof from a lateral roentgenogram of the knee in full extension. The roof impinged group consisted of nine patients who had the tibial tunnel placed anterior to the tibial intersection of the slope of the intercondylar roof. The unimpinged group was composed of eleven patients who had the tibial tunnel placed posterior and parallel to the slope of the intercondylar roof. MR scans were obtained at 0-2, 12, 24, 36, and greater than 48 weeks postoperatively. The signal intensities of grafts in both groups were identical at 1 week, but increased in the impinged group by 3 months and remained increased at 12 months postoperatively (p less than 0.01). In contrast, the MR signal of grafts in the unimpinged group remained unchanged during the first year. Knees with impinged grafts had extension deficits but remained stable. Roof impingement was impossible to view directly with the knee in full extension.(ABSTRACT TRUNCATED AT 250 WORDS)


Arthroscopic surgery of the knee: its role in the support of U.S. troops during Operation Desert Shield on USNS mercy.

The role of arthroscopy in the preconflict deployment of a large number of military troops is not well defined. Between September 1990 and January 1991, while deployed to the Persian Gulf for Operation Desert Shield 73 patients underwent on-board elective arthroscopy on the USNS Mercy. There were 71 men and two women with an average age of 27 years (range 19-47). Indications for arthroscopy included clinical diagnosis of meniscus tear, acute hemarthrosis, chronic effusion, and intra-articular loose body. Findings at the time of arthroscopy included 34 patients (47%) with meniscus tears; 17 (23%) with anterior cruciate ligament tears; five (7%) with isolated grade II-IV chondromalacia involving the patella, trochlea, femoral condyles, or tibial plateaus; six (8%) with synovitis; four (5%) with osteochondritis dissecans of the medial femoral condyle; two (3%) with a medial retinacular tear secondary to patella dislocation; and 10 (14%) with normal arthroscopic examinations. Forty-nine patients (66%) were returned to duty at an average of 6 days postoperatively, obviating the need to evacuate these patients from the Middle East theatre.


A potential complication of endoscopic carpal tunnel release.

Complications of carpal tunnel release have been well documented in the literature. Recently, a procedure for endoscopic release of the transverse carpal ligament has been described. This case report demonstrates a potential complication of endoscopic carpal tunnel release, in which the flexor digitorum superficialis tendon to the ring finger was nearly cut when the arthroscopic trocar passed beneath it. The procedure was converted to an open carpal tunnel release when the transverse fibers of the carpal ligament were not seen after several passes of the trocar. This complication was related to the inability to fully extend the wrist and metacarpophalangeal joints because of arthritic contractures. This case underscores the need for accurate identification of endoscopic anatomy prior to release of the carpal tunnel. The surgeon should not hesitate to convert to open technique if it becomes necessary.


Cystic degeneration of the patella after arthroscopic chondroplasty and subchondral bone perforation.

Chondromalacia of the patella is frequently encountered in patients with anterior knee pain. Arthroscopic chondroplasty with perforation of subchondral bone remains a popular treatment alternative in spite of the inferior mechanical properties of the fibrocartilaginous tissue that this procedure is designed to promote. We report a case of cystic degeneration of the patella as a previously unrecognized complication following the procedure.


Arthroscopic resection of chondroblastoma of the knee.

We present a case of chondroblastoma of the upper tibia treated by complete arthroscopic excision. The diagnostic difficulties raised by the case are discussed. This method of treatment has not, to our knowledge, been reported in the literature.


Arteriovenous fistula after arthroscopic synovectomy in a patient with haemophilia.

Arteriovenous fistula is a rare complication of arthroscopy. We report a human immunodeficiency virus-positive person with haemophilia who 19 months after an arthroscopic synovectomy of the knee presented with increasingly frequent haemarthroses and a palpable thrill over the knee. Angiography confirmed an arteriovenous fistula. The patient was successfully treated by surgical ligation of the communicating vessels. The literature regarding vascular injuries after arthroscopy of the knee is reviewed.


Arthroscopic roofplasty: a method for correcting an extension deficit caused by roof impingement of an anterior cruciate ligament graft.

Intercondylar roof impingement should be suspected in any patient having difficulty regaining knee extension following an anterior cruciate ligament (ACL) reconstruction. An arthroscopically performed roofplasty can eliminate the clinical complaints. The extent of bone removal can be planned from studying a lateral radiograph taken with the knee in terminal extension. Extension exercises or passive extension devices should not be used in patients with extension deficits caused by roof impingement because they may further damage the graft.


Tibial bone plug nonunion: a cause of anterior cruciate ligament reconstructive failure.

Anterior tibial tunnel placement contributed to the failure of two previous anterior cruciate ligament reconstructions. An allograft patellar bone-tendon-bone nonunion within the tibial tunnel caused dysfunctional ligament laxity. This is the first report of this type of reconstructive cruciate ligament failure.


Midcarpal arthroscopy: anatomy and technique.

Wrist arthroscopy has had a dramatic impact in both evaluation and treatment of a variety of wrist problems. Wrist arthroscopy has typically meant arthroscopy of the proximal wrist joint; however, midcarpal joint arthroscopy is becoming a routine part of a complete arthroscopic examination of the wrist. Specific indications, pertinent anatomy, and a clear technique for performing a midcarpal arthroscopy is not well documented in the literature. This article attempts to offer some insight on these issues.


Oxidative energy metabolism in Alzheimer brain. Studies in early-onset and late-onset cases.

Reduction of the cerebral metabolic rate of glucose is one of the most predominant abnormalities generally found in the Alzheimer brain, whereas the cerebral metabolic rate of oxygen is only slightly diminished or not at all the beginning of this dementive disorder. This metabolic abnormality may induce severe functional disturbances, obviously preceding morphobiological changes. From the cerebral metabolic rates of oxidized glucose and oxygen, the cerebral ATP formation rate was calculated in incipient early-onset, incipient late-onset and stable advanced dementia of Alzheimer type. A reduction of ATP formation was found from at least 7% in incipient early-onset, to around 20% in incipient late-onset DAT, and from 35% to more than 50% in stable advanced dementia. This approximation was adjusted to findings demonstrating diminished activities of enzymes active in glucose metabolism and formation of oxidation equivalents for ATP production from substrates other than glucose. A reduction for energy formation to the same range was found, as was also recently reported, in vivo in Alzheimer patients. From this rather theoretical point of view, a permanent loss of energy by at least 7-20% in incipient and progressively advancing dementia of the Alzheimer type may be assumed, with an increasing tendency in stable advanced dementia to around 50% energy loss. This energy deficit may have drastic impacts on brain function.


Expression of protease nexin-II in human dorsal root ganglia. A correlative immunocytochemical and in situ hybridization study.

Protease nexin-II (PN-II) is a potent chymotrypsin inhibitor that forms SDS-stable inhibitory complexes with epidermal growth factor binding protein, the gamma-subunit of nerve growth factor, and trypsin, and represents the secreted form of the amyloid beta-protein precursor (APP) that contains the Kunitz-type protease inhibitor domain. To determine the expression of PN-II within the peripheral nervous system, human dorsal root ganglia were processed for immunocytochemistry using well-characterized monoclonal antibodies against PN-II and for in situ hybridization studies using 35S-RNA PN-II probes for both APP751 and APP770. Highly specific immunoperoxidase staining of PN-II was demonstrated within the cytoplasm of dorsal root ganglia neurons and their processes in cryostat (fresh frozen) and vibratome (paraformaldehyde-fixed) sections. In situ hybridization using an anti-sense 35S-RNA PN-II probe demonstrated the presence of intense neuronal labeling. Labeling was not observed when the corresponding sense 35S-RNA PN-II probe was used. Although the precise functional role of PN-II/APP is not clear, the accumulation of amyloid beta-protein within the neuropil appears to be one of the earliest events in the pathogenesis of Alzheimer's disease (AD). Thus knowledge of the cell populations expressing the PN-II/APP gene would certainly be helpful for studies of the molecular mechanisms leading to the morphological and functional changes of AD. The results of this study clearly establish the expression of PN-II and its mRNA within the dorsal root ganglia neurons and their processes, and provide another point of departure for studies of the molecular mechanisms underlying the deposition of amyloid beta-protein and its relationships to the formation of neuritic plaques and neurofibrillary tangles.


Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant paralytic tremor rabbit myelin.

Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant, paralytic tremor (PT) rabbit myelin and premyelin fractions was studied using immature (4-5 wk) or adult animals. The enzyme was estimated by determination of its catalytic activity as well as by using immunoblot analysis after SDS-PAGE separation. The presence of two forms of CANP--one activated by calcium in the micromolar concentration (mu CANP) range and the other exhibiting low calcium sensitivity in the millimolar concentration range (m-CANP)--was found in the myelin and premyelin fractions. The developmental pattern of the enzyme activity was different for each of these two enzyme isoforms depending on the fraction studied. The higher activity on CANP (both isoforms) found in PT myelin and premyelin could be related to delayed myelination and/or to the higher turnover rate of already formed myelin. These results suggest complex and specific roles for these isoenzymes during myelin formation as is discussed further in this article. Our results confirm the extensive degradation of myelin basic protein (MBP), proteolipid protein (PLP), and, to a lesser extent, the other myelin proteins by endo- and exogenous CANP. This degradation process was significantly elevated in PT rabbit myelin. Moreover as was shown by two-dimensional gel electrophoresis, calcium-controlled proteolysis in nonmutant rabbits affected the net-charge of MBP in a manner similar to that reported for PT myelin, suggesting the possible involvement of CANP in the generation of charge isomers of MBP.


Contributions to neurochemical knowledge considered ecologically.

The development of neurochemical knowledge is traced through the following stages: (1) Beginnings with academic medicine: a dissertation of 1719, (2) Relations with chemistry and scientific journals of around 1800, (3) A review and the naming of neurochemistry in 1856, (4) Government publication of neurochemistry; a full-time chemist of the brain, (5) Success in a biochemical environment, 1900-1940, (6) Neurochemistry with the neurosciences, (7) Neurochemical environments of 1955-1957.


Ganglioside distribution in murine neural tumors.

The ganglioside composition of seven experimental brain tumors was examined in C57BL/6J mice. The tumors were produced from 20-methylcholanthrene (20-MC) implantation into either the cerebrum or cerebellum and were maintained in serial transplants through many generations. The tumors studied were grown subcutaneously as solid tumors, and cells from two of the tumors were also studied in culture. Histologically, all of the tumors were similar and could be broadly classified as highly malignant, poorly differentiated anaplastic astrocytomas. The total ganglioside sialic acid content of the solid tumors was markedly lower than that in adult mouse brain. In addition to N-acetylneuraminic acid (NeuAc), the gangliosides in the solid tumors contained significant amounts of N-glycolylneuraminic acid (NeuGc). The seven solid tumors fell into two general groups with respect to ganglioside composition. Furthermore, the differences in ganglioside composition between the two tumor groups were strongly associated with differences in tumor cell cohesion. The tumors in one group had high levels of GM3 hematosides, low levels of oligosialogangliosides, and grew as firm cohesive tissues. The tumors in the other group, however, had lower levels of GM3 hematosides, noticeable amounts of oligosialogangliosides and grew as soft noncohesive tissues. In culture, clonal cells from one of the tumors in the first group grew as clumps or islands and contained GM3 as the only major ganglioside, whereas clonal cells from a tumor in the second group grew as sheets or monolayers and contained little GM3, but expressed several gangliosides with complex structures. In marked contrast to the gangliosides in the solid tumors, the gangliosides in the cultured tumor cells contained trace amounts of NeuGc. Since NeuGc containing gangliosides are abundant in mouse nonneural tissues, the high content of NeuGc gangliosides in the solid tumors may arise from infiltration of nonneural tissue elements, e.g., macrophages, lymphocytes, and endothelial cells.


The effect of lipoproteins on human glioblastoma growth in vitro.

Experiments were performed using an established human glioblastoma cell line to determine the effect of lipoproteins on regulating their growth. It was found that synthetic and natural human high density lipoproteins (HDL) were effective in inhibiting tumor cell growth in a nontoxic, dose-dependent manner, and that the LD50 was 10-fold lower than that for normal rat astrocytes grown under identical conditions. In the presence of the antioxidant, glutathione, essentially all of the growth-inhibiting properties of HDL could be reversed suggesting that oxidized lipids from the HDL interacting with the plasma membranes of the glioblastoma cells were responsible for the growth-inhibiting effect observed. The markedly lower concentration of HDL required to inhibit glioblastoma cells in culture compared to normal astrocytes suggested that the mechanism of HDL-induced inhibition may be important for tumor growth in vivo. One possible mechanism under investigation is the possibility of HDL modulation of a membrane-associated, tumor-specific phosphatase.


[Legal cases on the correlation between exposure to asbestos fiber dust and laryngeal cancer].

In Germany the causal relationship between laryngeal carcinoma and occupational exposure to asbestos is under discussion. We report on 30 cases of laryngeal carcinoma for which compensation was considered, since an occupational contact with asbestos was confirmed or suspected. We looked especially for signs of non-tumorous lesions related to asbestos exposure in radiography or CT of the chest. Such signs could be detected in 12 individuals. In Germany compensation for an occupational disease can be granted only, if e.g. the relevance of asbestos exposure is sufficiently probable, with special regard to other noxious influences such as cigarette abuse. Asbestosis of the larynx cannot be diagnosed specifically; we, therefore suggest proving the relevance of asbestos exposure in respect of signs of tumorous or non-tumorous lesions in the chest.


[Mucoepidermoid cancer of the larynx. Case report and review of the literature].

Mucoepidermoid carcinoma (MEC) is classified among the salivary gland tumours and is most commonly found in the parotid gland. It rarely occurs in the larynx. There have been only 87 cases of laryngeal MEC reported in the literature. We report on an MEC of the vocal cord in a 75-year-old man, with a thickened right vocal cord without any loss of movement. The initial diagnosis was squamous cell carcinoma. One year after radiotherapy a tumour recurrence developed. Because the patient refused to laryngectomise, a tumour resection with the CO2 laser was performed twice. To date, the patient has been free from disease for more than five years. The true incidence of this type of neoplasm could be higher than is believed because of its frequent misdiagnosis as squamous cell carcinoma.


[Nystagmus reactions after rotatory vestibular stimulation (modified Veits long-term rotation) in patients with normal equilibrium. Part I: Absolute values of the nystagmus reactions].

In this study the nystagmographic findings of 70 healthy subjects--obtained after having used the rotatory test (modified method of Veits)--are summarised and visualised by means of easily appreciated graphs. In accordance with the recommendations of the ADANO, the test was carried out as a continuous turning of the chair, first clockwise and then counterclockwise, with an accelerating stimulus of 3 degrees/s2 and a sudden stop after a period of constant rotation with a speed of 90 degrees/s (trapezoidal stimulus). This was done for the absolute values of the following nystagmus parameters: frequency, amplitude and slow phase velocity of the nystagmus reaction. The limits of a normal nystagmus reaction are evaluated by the 5%- or 95%-percentiles on the one side and the mean values combined with the standard deviation mean value +/- 2 standard deviations on the other. It is shown that the rotatory test with its different phases enables very sensitive selection between healthy subjects and patients with an acute peripheral vestibular lesion. The intraindividual variability of the nystagmus reactions proved to be lower than that between our control persons (interindividual variability). By our method of employing the rotatory test it can be shown that the interfering phenomenon of habituation does not influence the nystagmographic results.


[Histological studies of the behavior of the dentin ossicular prosthesis in the human middle ear].

The Dentine Ossicular Prosthesis (DOP)--introduced in the ENT-Department, University of Hamburg in 1986--has proved its worth clinically in more than 300 cases. In the meantime six of the prostheses had to be removed for various reasons. They had remained in the middle ear over a period between 2-5 and 47 months. The prostheses were investigated undecalcified by the Donath sawing and grinding technique. Prostheses in a nearly bland surrounding show a partial invagination in fibrous connective tissue without severe reaction of the prosthesis itself, whereas in prostheses removed from the neighbourhood of inflammatory processes or recurrent cholesteatoma a partial resorption of dentine with subsequent new bone formation could be observed. Due to the trouble-free clinical and histological performance in the human middle ear, the Dentine Ossicular Prosthesis can be well recommended as an alternative material in ossiculoplasty.


[Acute tonsillitis--peritonsillitis--paratonsillar abscess: Differential diagnosis by flexible endosonography].

The role of flexible endosonography in diagnosis of acute tonsillitis and their complications was investigated in 59 patients. Our results show that flexible endosonography enables the examiner to differentiate acute tonsillitis from peritonsillitis and paratonsillar abscess. In particular, abscesses of retrotonsillar spread possibly leading to life-threatening complications can be detected in an early stage.


[The diagnostic value of nuclear magnetic resonance tomography in Sjögen's disease].

Sjögren's syndrome is characterised by xerostomia, xerophthalmia and recurrent parotid swelling. There is a high coincidence with rheumatoid diseases. A variety of clinical and laboratory parameters offers important information for diagnosis, but none of them is specific for this disease. 36 patients with clinical diagnosis of Sjögren's syndrome were examined in a prospective study to evaluate the diagnostic significance of this technique. 34 patients showed an inhomogeneous, nodular pattern in the parotid gland. The signal intensity was very high, especially in the T2-weighted sequences. There was a significant correlation of the radiologic changes with the course of the disease. Four patients with the clinical diagnosis of sialadenosis demonstrated bilateral enlarged glands with a homogeneous signal pattern. Patients with acute purulent parotitis demonstrated enlargement of the gland without an alteration in the signal pattern. Patients with chronic recurrent parotitis and patients with radiogenic sialadenitis showed little inhomogeneous increase of signal intensity. Our results indicate that MRI is presently the radiological method of choice in the evaluation of Sjögren's syndrome.


[Evoked otoacoustic emissions as a screening test for hearing evaluation in newborn and premature infants?].

The purpose of this study was the evaluation of evoked otoacoustic emissions (EOAE) for the screening of infant hearing. EOAE and brainstem-evoked response audiometry (BERA) were performed in 40 infants at a special care unit at the Universitäts-Klinik, Göttingen. Both examinations were performed under non-optimal conditions, reflecting a realistic screening situation. The purpose was to determine robust analysis criteria and possible error sources. A comparison of both tests shows that sensitivity and specificity are insufficient for reliable screening. The EOAE test does not yield the threshold of hearing. There is no sharp boundary with the BERA threshold for the detectability of an EOAE. Sensitivity and specificity have not been accurately determined so far due to the relatively small number of infants with impaired hearing tested. Nevertheless, the results show that EOAE should be applied as a supplement to conventional audiometry for infants. It is capable of excluding conductive and severe cochlear hearing losses and is by itself not a reliable screening test.


[Comparative speech audiometry studies with compact disk].

We compared the results of speech audiometry, performed with recorded tape and CD, respectively, in 21 subjects with bone conduction hearing loss, and in 27 subjects with sensorineural hearing loss. In all cases, speech audiometry was performed by using the German Freiburg speech test material, recorded in 1969 on the basis of the German DIN standard 45626. In subjects with an air-bone gap, the hearing loss for speech is 2.3 dB smaller if tested by use of CD, and the speech recognition is 10.5 points better, respectively. Smaller differences could be found in sensorineural HL: For CD, the hearing loss is 1.2 dB smaller, and the speech recognition score is raised by only 1 point. These differences are statistically not significant, and the calculation of hearing impairment and individual hearing handicap from the tables commonly used in Germany in medicolegal expert opinions must not be corrected, if records on CD are used basing on the recordings from 1969 according to DIN 45626. The handling of compact discs has many advantages in relation to the handling of tapes.


[Norrie-Wardburg syndrome].

We describe a case of a 25-year old patient with typical Norrie-Warburg Syndrome. From the first year of his life he was found to be blind, with bilateral sensorineural loss of hearing. Audiological examination showed symmetrical moderate bilateral sensorineural hearing loss. His hearing loss was refractory to treatment for the last eight years. Because of timely diagnosis of hearing loss and timely fitting of a hearing aid, the patient could study at school and graduate from university education. Disease carriers who are clinically healthy can be identified only via chromosome analysis.


[Morphologic aspects of the maturation of the sensory areas of the cerebral cortex exemplified by the visual cortex of the rabbit].

When the cerebral cortex commences its earliest functional tasks, the cellular layers and the basic organisation pattern of cell processes have already developed. In the rabbit visual cortex it could be shown that the functional differentiation runs parallel to an increase in number and growth of cell processes. Those tissue compartments where the newly formed branches of the dendritic trees of cortical neurons come into contact with the axons arising from other cerebral regions, grow between two and six times larger depending on the cortical layer where their volume fractions are measured. Cell processes grow and increase in number most rapidly between the second and the fourth postnatal weeks. Myelination of fast conducting axons takes longer and attains an adult level about three month after birth. Then the visual cortex of the rabbit may be regarded as mature with regard to both structure and function.


Renaissance for hapten-specific T lymphocytes: implications for basic and applied research.

Protein-reactive chemicals and drugs (haptens), such as dinitro- (DNP) or trinitro-phenylated (TNP) reagents or penicillins, are potent inducers of allergic reactions in experimental animal systems as well as in humans. Hapten-specific T lymphocytes are mediators of these disorders. Like other antigens, hapten determinants on target cells are recognized by the T cell's antigen-specific receptors exclusively in association with gene products of the major histocompatibility complex (MHC). Until recently, the nature of the complex hapten/MHC determinants remained unknown. Atypically, this fact, rather than spurring scientific investigations, caused a rapid loss of interest in haptens as T cell antigens by the majority of immunologists. This situation may now be changing, since we have recently identified MHC-binding, hapten-modified peptides which mediate cellular recognition by T cells via their antigen-specific receptors. Synthetic hapten-peptide conjugates open up new routes in studying the molecular details of hapten recognition by T cells. They may also contribute to a better understanding of what defines an antigen as an allergy-inducing "allergen".


7-Desmethyl-microcystin-RR, a hepatotoxin from a waterbloom of Microcystis aeruginosa.

A peptide toxin was isolated from a waterbloom of Microcystis aeruginosa from Lake Frøylandsvatn in Norway. The isolation procedure included liquid and solid phase extraction and reversed phase high performance liquid chromatography. Amino acid analysis yielded D-glutamic acid, D-erythro-beta-methylaspartic acid and D-alanine in equimolar and L-arginine in twofold molar ratios. The presence of dehydroalanine was confirmed by hydrogenation and subsequent amino acid analysis with combined gas liquid chromatography/mass spectrometry. Investigation of the toxin with fast atom bombardment mass spectrometry showed a nominal relative molecular mass of 1023. 3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyl- 4,6-decadienoic acid (Adda) was identified by 1H NMR and 1H, 1H COSY spectroscopy. The structure of the toxin was elucidated as 7-desmethyl-microcystin-RR.


Non-essential activation of rat liver porphobilinogen-deaminase by folic acid.

This report demonstrates the ability of folic acid to activate rat liver porphobilinogen-deaminase (PBG-D). Lineweaver-Burk analysis revealed an increase in Vmax (38%) without affecting the Km. In the concentration range assayed, secondary replots of 1/delta slope and 1/delta intersect versus 1/[folic acid] yielded straight lines, indicating the binding of a single molecule of activator to the enzyme PBG-D, with a KA = 1.66 mM. Results presented here show that folic acid acts as a non-essential activator (alpha = 1; beta = 1.6). The activating effect of folic acid has been observed employing the 35-70% ammonium sulphate precipitated fraction, desalted by dialysis or gel filtration, whereas no action was detected when other partially purified PBG-D preparations were utilized as the enzyme source, suggesting either the presence of sites saturated for the activator, or the existence of a different structural protein conformation, or both.


Effects of chloroquine on the photosensory membrane turnover and the ultrastructure of lysosome-related bodies of the crayfish photoreceptor.

The effect of chloroquine in combination with bright light on the ultrastructure of crayfish (Orconectes limosus R.) photoreceptors was investigated in vivo. Chloroquine had several effects upon the crayfish retina. Multivesicular bodies (MVB) that are involved in lysosomal degradation of photosensory membrane were altered in ultrastructure. MVB frequently contained smaller MVB in a state of more advanced membrane degradation. Additionally screening pigment-like granules appeared in MVB. MVB accumulated in and filled the retinular cell cytoplasm just proximal or distal to the basement membrane which indicated inhibition of photosensory membrane degradation. Under chloroquine treatment rhabdom degradation appeared to be inhibited, as rhabdom diameter was less reduced under these conditions. Also chloroquine caused accumulation of screening pigment granules in glial cells within the lamina ganglionaris.


Ferredoxin-NADP+ oxidoreductase of C. paradoxa nucleus encoded, but cyanobacterial gene transfer from symbiont to host, an evolutionary mechanism originating new species.

The nucleus encoded cyanoplast ("cyanellar") ferredoxin-NADP + oxidoreductase (FNR) of Cyanophora paradoxa, characterized by an N-terminal amino acid sequence, is compared with homologous sequences of other photoautotrophic organisms. The high degree of similarity to the cyanobacterial sequences indicates a cyanobacterial origin. This could be a first direct demonstration of an intertaxonic combination: a gene transfer from an original endocytobiont (cyanobacterium) to the nucleus of its host, one of the most important demands of the Endosymbiosis Theory, an evolutionary mechanism leading to the origin of a new species.


Modulation by ryanodine of active calcium loading and caffeine induced calcium release of heavy sarcoplasmic reticulum vesicles.

The effect of ATP on the calcium release channel in heavy sarcoplasmic reticulum vesicles modulated by ryanodine has been analyzed by monitoring active calcium uptake and caffeine induced calcium release under near physiological conditions. Native as well as ryanodine reacted vesicles display a complex time course of calcium uptake resulting in nearly complete exhaustion of medium calcium when ATP in combination with an ATP-regenerating system, in contrast to ATP alone, or dinitrophenyl phosphate, were used to support calcium uptake. Applying of dinitrophenyl phosphate as energy yielding substrate, not affecting channel activity, allowed to estimate the fraction of light vesicles devoided of calcium channels contaminating the heavy preparation as the fraction that stores calcium after the preparation has been treated with channel opening, low concentrations of ryanodine (1 microM). Calcium uptake by contaminant light vesicles (25%) cannot account for calcium storage, as well as, abolition of caffeine induced calcium release of ryanodine treated heavy vesicles. Calcium uptake of native and ryanodine treated vesicles is accompanied by the uptake of equivalent amounts of inorganic phosphate arising from ATP hydrolysis indicating that calcium is mainly stored as calcium phosphate. The momentary capability of the preparation to accumulate calcium was measured by activating calcium uptake during the calcium storage period with 0.2 mM 45CaCl2 and 4 mM phosphate at short time intervals. A significant increase of the momentary uptake activity with time was observed being more pronounced for ryanodine treated than for native vesicles indicating that under regenerating conditions, ATP can induce closing of the native and even more effectively of the ryanodine modified calcium release channels.