[Experimental studies of the effect of carbon monoxide on the retina of guinea pigs of different age].

Young and adult guinea pigs had been put in a chamber containing an 4-5 per cent addition of CO in the air. After 7 days of intoxication the authors performed a histopathological and histochemical examination of the retina. They discovered disturbances of the histological structure of the retina, a decrease of the content of nucleic acids and alkaline phosphatase and an increase of the acid phosphatase. The more pronounced intensification of the pathological changes was seen in the retina of younger individuals.


[Effect of drugs inhibiting the formation of hydroxide radicals on healing of experimental corneal ulcer].

The 60 per cent water solution of dimethyl sulfoxide (DMSO) was used in the investigations. It was instilled into the conjunctival sac of an eye with experimental corneal ulceration. The dimethyl sulfoxide is inhibiting the formation of hydroxide radicals which cause a damage of the tissue in the course of inflammation. Clinical observations as well as histochemical and histopathological examinations showed that ulcerations treated by dimethyl sulfoxide healed faster than those from the control group and reactions to acid mucopolysaccharides++ returned more rapidly to normal values.


[Measurement of lens transparency in workers at risk of developing of glassblower's cataract].

The authors evaluated the transparency of lenses in persons on a stand predisposing to the formation of a glassblower cataract as well as in office clerks. They used for their measurements a fluorophotometer (Fluorotron Master) and an opacity lensmeter. In a group of 40 ironmasters they found a considerable fall in light transparency through the lens and a significant increase of the lens autofluorescence in comparison with a group of office clerks. The quantitative measurement of lens transparency by means of a fluorotron and a opacity lensmeter creates the possibility of an earlier detection of a ++pre-cataract condition.


[Condition of the corneal endothelium after penetrating injuries].

The examination of the corneal endothelium with a posttraumatic scar was performed by means of a corneal microscope with an endothelial cell counter in patients with traumatic cataract before its removal with simultaneous implantation of an artificial intraocular lens. It was established that the density of the endothelial cells in these eyes before surgery amounted 950-3000/mm2. The density of the cells below this value creates a danger of formation of bullous keratopathy after the surgical intervention.


[Study od visual evoked potentials in employees of the Chemical Works in Bydgoszcz].

Examined was a group of 50 persons aged 25-60 years employed in the Chemical Works in Bydgoszcz. The time of professional contact counted from 4 month to 31 years. During this time the workers had contact with the following--at least 2--compounds: chlorine and its derivates, benzene, propylene, katolite, phosgene, isocyanianes, epichlorohydrine and others. In 33 among 50 examinees (66 p.c.) the authors detected a normal record of VEP. A pathological record was observed in 17 persons (34 p.c.). The greatest per cent of pathological records concerned a group of professional practice amounting 20-29 years as well as persons undertaking the work before the 25th year of life. The most frequent pathological record of VEP was a curve with reduced amplitude of the P wave; the least frequently seen was the debasement of the amplitude together with the elongation of the latent time of this wave.


[Analysis of the place of regulation of C-11 transmitters at the Tele-electronic Works "Telkom-Telfa" in Bydgoszcz from the point of view of visual hygiene].

The authors performed a detailed analysis of 100 positions of regulation of the C-11 transmitters in the "Telcom-Telfa" ++Tele-electronic Works in Bydgoszcz. It was determined that the requirements for the condition of the eyes and the lighting at this workstand are considerable. Conclusions and recommendations tending to improvement of the working conditions are drawn up. Proposed is eventual rationale leading to the reduction of the eyestrain and facilitation of the work.


[The incidental heart sound. Study of clinical diagnostic certainty and possible causes].

The diagnosis "innocent murmur" is made when there is no evidence for a heart disease either by history nor by examination, auscultation, electrocardiogram or echocardiography. The purpose of the present study was to determine the usefulness of echocardiography for diagnosing of an innocent heart murmur and further to compare the findings of ultrasound with those of the clinical examination. Children were accepted for the study after clinical examination and evaluation of the electrocardiogram (but before echocardiography) only when two independent pediatricians did not realize any symptoms of a heart disease. A total number of 200 children were examined; 121 were male and 79 female. 194 children (97%) had an innocent murmur, six children (3%) a heart disease [atrial septum defect (3), bicuspid aortic valve (1), aortic stenosis (1) or pulmonary stenosis]. The sensitivity and positive predictive value of clinical examination and auscultation ranged from 92% to 99%, the specificity from 50% to 60%. In six cases the initial diagnosis had to be changed after echocardiography. Three times an innocent murmur was diagnosed as a heart disease and another three times a pathological murmur was regarded as innocent. Left ventricular bands were seen in 53 (26,5%) children and they significantly correlated with the musical heart murmur (77%). If there was no false tendon, the murmur was mostly an uncharacteristic one (74% (less than 0,001). The echocardiographic findings were not different of those children without a murmur or heart disease. The average peak velocity in the ascending aorta was 143,1 +/- 23,6 cm/s (87-215 cm/s), the shortening fraction 36,2 +/- 6,3%. We could not find a correlation between velocity, shortening fraction and aortic diameter.


[Bland-White-Garland syndrome. Clinical aspects, diagnosis, therapy].

The anomalous origin of the left coronary artery from the pulmonary artery (Bland-White-Garland Syndrome) is a rare congenital malformation reported to occur in 0.25-0.5% of all congenital cardiac anomalies. The clinical and pathomorphological picture can be classified into 2 types: infantile or adult. The infantile type is thought to lack coronary collaterals; this explains the bad prognosis and symptoms of non-operated patients. In the adult type collaterals are present or have developed in time to provide adequate blood supply to the myocardium. No history of cardiac complains and a nearly normal ECG are common findings. Echocardiography and cardiac catheterisation are mandatory diagnostic tools. The value of new methods like NMR, "stop-flow" angiography and color doppler flow mapping is still in discussion. The reimplantation of the coronary artery and Takeuchi-Operation are well established surgical methods. The time for the operation and prognostic outcome are related to the preoperative underlying myocardial damage measured by left ventricular function.


[Alcohol in pregnancy and fetal heart damage].

Alcohol abuse and addiction during pregnancy can induce damage of the heart muscle and heart defects in the offspring. Between 1973 and 1991 216 children with fetal alcohol syndrome were diagnosed and examined for congenital heart defects. In 63 children (= 29,1%) heart defects were present, established mainly by heart catheterization and/or echocardiography. Most frequently ventricular septal defects (24/63) and atrial septal defects (23/63) occurred, less frequent were AV-defects (3), PDA (3), Fallots teralogy (5), and other malformations (5). Biopsy during heart surgery in 3 children revealed histological and electron microscopic changes of alcohol-cardiomyopathy. Heart defects are predominantly found in children with higher degree of severity concerning the clinical syndrome, less frequently in alcohol effects (4/38 = 11%). Alcohol in pregnancy, even in the course of so called social drinking, usual drinking and binge drinking has to be considered as an essential and preventable co-factor within the multifactorial etiology of congenital heart defects.


[PCB exposure of children in East and West Germany].

In order to assess the exposure to polychlorinated biphenyls (PCB) in children from East- and West-Germany 276 fat tissue samples were analysed. Total PCB concentrations were calculated by means of six PCB congeners: No. 28, 52, 101, 138, 153 and 180. In children from East-Germany the mean total PCB levels amounted to 0.899 mg/kg (median 0.674) and were significantly higher than in children from West-Germany (0.766/0.555 mg/kg; p less than 0.05). Regional differences were only seen within East-Germany. In fat tissue of children with high intake of breast milk (lactation period greater than 12 weeks) PCB levels were significantly elevated compared to those with low intake of mother's milk (lactation period less than 12 weeks). A further reduction of PCB in our environment is necessary so that breast milk can be recommended for sucklings without any restrictions.


[Laser Doppler flowmetry in newborn infants with low birth weight. The effect of differences in humidity on peripheral circulation].

In a group of 10 low birth weight infants we measured skin temperature using infrared thermography and laser Doppler flow in central and peripheral regions of the body. After elevation of incubator humidity from 40 to 80% skin temperature of the foot rose significantly (p less than 0.01). At the same time there was a significant increase (p less than 0.05) of laser Doppler flow. Temperature and laser Doppler flow in the area of the abdomen did not show significant changes. Low birth weight infants are able to regulate peripheral blood flow after changes of ambient humidity. With the method of laser Doppler flowmetry thermoregulatory responses in the microvascular bed can be measured in these infants.


[Neurosonographic findings in premature infants and infants with intrauterine growth retardation with a birth weight below 1,500 grams].

The cranial ultrasound of 111 preterm infants were reviewed. 57 patients were appropriate for gestational age (AGA) and 54 small for gestational age (SGA). In the two groups, the incidence of peri-intraventricular hemorrhage (PIVH), posthemorrhagic ventricular dilation (VM) and peri-ventricular leucomalacia (PVL) was compared. PIVH was more common in AGA than in SGA babies (36.8% vs 18.5%). In both groups (AGA and SGA), birth weight less than 1000 g should be considered a further risk factor for hemorrhagic brain lesion (72.2% in AGA babies less than 1000 g and 20.5% ind AGA babies greater than 1000 g birth weight, p less than 0.01) (34.8% in SGA babies less than 1000 g and 6.4% in SGA babies greater than 1000 g birth weight, p less than 0.05). However, ischemic brain lesions (PVL) were not dependent from birth weight (p greater than 0.5). This study shows that low birth weight infants are an eterogeneous group of babies with different risk of hemorrhagic or ischemic cerebral lesion depending on gestational age and birth weight.


[Progress and change in nuclear magnetic resonance diagnosis of congenital and acquired heart defects].

Since 1987, the authors have examined 186 patients (76 girls, 110 boys) with a variety of congenital and acquired heart diseases by means of magnetic resonance imaging (MRI). The patients' ages ranged from 2 days to 20 years (mean age 3.97 years). During the study new techniques were developed, which extend the applicability of MRI. Especially two-dimensional and three-dimensional angiography are demonstrated and discussed. Using all diagnostic tools offered by MRI more than 90% of cardiovascular malformations are correctly diagnosed. MRI is of unquestionable value in the evaluation of the thoracic and abdominal aorta and in demonstrating the vascular status in pulmonary atresia and anomalous pulmonary venous return. It may be useful if question arise in patients with complex lesions, intra- and extracardiac tumours and cardiomyopathies. Although MRI is still under investigation, it may play a major role in diagnosing congenital heart diseases.


Large amounts of 1 beta-hydroxylated bile acids in urine during taurine therapy.

The management of infants with cholestasis remains a difficult challenge. On the hypothesis that taurine is effective in treating neonatal cholestasis, taurine (1 g/day, per os) was administered to 2 patients with neonatal hepatitis and the bile acids were analyzed using gas chromatography-mass spectrometry (GC-MS). The serum levels of bilirubin and bile acids were significantly decreased by taurine. Before the treatment, cholic acid (CA) and chenodeoxycholic acid (CDCA) were predominant (79.2% in both patients) in the urine. There was a significant elevation of 1 beta-hydroxylated bile acids (1 beta BA), especially 1 beta, 3 alpha, 7 alpha, 12 alpha-tetrahydroxy-5 beta-cholan-24-oic acid (CA-1 beta-ol), in urine collected during the taurine therapy, and 1 beta BA became predominant (57.7-78.3%). Therefore, increased amounts of urine 1 beta BA were excreted during taurine administration. Taurine therapy is recommended, because it might be effective for treating neonatal cholestasis.


[Is outdoor running exercise suitable for detecting bronchial hyperreactivity in children with mild episodic bronchial asthma?].

Bronchial hyperreactivity (BHR) can be proved by various methods. 21 children, 14 asthmatics and 7 healthy subjects were submitted to inhalative methacholine challenge as well as to 'free running' as a form of exercise challenge in a randomized sequence. For the methacholine inhalation a standardized procedure was followed and the provocative concentration defined (PC20) at which a decrease of more than 20% in FEV1 was found. There is no real standardisation for 'free running' (concerning temperature and humidity of the inspired air; individual level of exercise) but subjects had to run for 6 minutes while the heart rate should have been between 170 and 180 beats/minute. This increase in pulse rate relates to a submaximal work at which 60-85% of maximal O2 uptake are obtained. A decrease of 15% from basic value of FEV1 was defined as a positive result. By the use of methacholine inhalations we found 16 children (14 diseased, 2 controls) to be hyperreactive, whereas only 3 of them showed a positive result after 'free running'. We conclude, that firstly, methacholine provocations and exercise challenges assess different kinds of bronchial reactivity, secondly, 'free running' as a form of exercise is very difficult to standardize and therefore prone to errors and thirdly, 'free running' is not sensitive enough to assess BHR in children with mild asthma bronchiale if used as the only form of challenge. Problems concerning measurement of BHR are discussed.


The cystic growth of a subependymal giant-cell astrocytoma with tuberous sclerosis.

A case of a 7 year-old boy with subependymal giant-cell astrocytoma is reported. CT scanning of this patient for 6 years showed the cystic growth of the astrocytoma. The surgical indication and importance of periodic CT studies for subependymal giant-cell astrocytomas associated with tuberous sclerosis are discussed.


[Respiratory death space and ventilation of newborn infants].

The effect of dead space reduction was studied in 10 VLBW infants (GA 26-31 wks, mean BW 1100 grms) on mechanical ventilation using a constant flow ventilator with a flow sensor device (Draeger Babylog 8000, Lubeck, Germany). Shortening of the endotracheal tube and removal of the flow sensor resulted in a calculated 50% reduction of dead space (-2.3 ml) and in a fall of tcpCO2 from (mean and range) 45 (40-49) to 35 (31-36) mmHG. This corresponds to a increase of alveolar ventilation of 22% as predicted by calculation of the dead space changes. Further attempts were made in reducing dead space ventilation by using endotracheal tubes conceived for jet ventilation, using the jet entry for the inspiratory side, or by introducing a separate continuous inspiratory flow to the tip of the endotracheal tube. Besides a routinely performed shortening of the ET tube this means of ventilation was used with success in two VLBW infants with desperate respiratory situations who both survived, in an older infant with high-grade tracheal stenosis to wean him from the respirator and in three neonates with congenital diaphragmatic hernia in conjunction with delayed operative repair who could be weaned from respiratory support 4, 13 and 20 days post surgery. We conclude that dead space reduction is a means to achieve gentle ventilation and to reduce lung damage from artificial ventilation.


Pattern recognition of continuity of discrete data points by scale changed plots.

Graphs composed of a large number of data points plotted on an appropriate scale enables us to pattern recognize a specific continuous curve. This principle was used to follow signals from proton nuclear magnetic resonance as a function of pH in a large biomolecule, staphylococcal nuclease. The analysis was automated by auto peak-picking routines and by transferring the results to a graphic program, Graphic Operating System (Roome & Peterson, 1985). Expansion and contraction of the scale made it possible to differentiate specific tyrosine and histidine titration curves. This type of analysis is applicable for assignment of specific curves from a large number of data points which change as a function of perturbations.


[Measuring skin temperature in premature infants. Comparison of infrared telethermography and electric contact thermometry].

In a group of 6 premature infants, mean weight 1776 g, we measured skin surface temperatures, comparing infrared telethermography (San-ei Thermo-Tracer 6T62) and conventional skin thermometry (Eidatherm). Surface temperatures were measured at 10 different sites, with the infants nursed in an incubator. The same methods were used to compare temperatures on the lower arm of an adult. The results of the two different techniques showed only minor differences of approximately 0,2 degrees C. These discrepancies could be explained by problems of either method. They could also be attributed to the fact, that the emissivity of human skin is not exactly identical with the emissivity of a perfect black body. In clinical practice, infrared thermography and conductive thermometry can be used for determinations of body surface temperature of premature infants, also under the condition of high temperatures and high humidity within an incubator.


Immunological study of the association between hepatocyte damage and HBc antigen.

To identify the target antigen during hepatocyte damage in hepatitis type B virus (HBV) infections, the expression of HBc and HBs antigens, and beta 2-microglobulin (BMG) were studied in liver tissue. Serial changes of serum DNA-polymerase (DNA-P) activity and HBV DNA were also measured. After the onset of acute hepatitis, HBs antigen in liver tissues was observed from many patients; but HBc antigen was rarely detected. In liver tissues of patients with chronic hepatitis, HBs antigen was consistently positive, irrespective of the changes in sGPT. On the other hand, HBc antigen was frequently positive both preceding and during the culmination period for sGPT. The distribution of HBc antigen in the hepatocyte was mostly cytoplasmic. During the same period the serum DNA-P and HBV DNA were frequently positive. Immunoelectron microscopy showed that reaction products with HBc antigen existed in the cytoplasm and the cell membrane. These results indicate that HBc antigens become the target, when HBV infected hepatocytes are eliminated.


[Prenatal diagnosis of primary megaureter].

22 of 114 infants with prenatal diagnosis of urinary tract malformations (15 boys) had obstruction of the ureterovesical junction caused by primary megaureter (n = 14), ureterocele (n = 7), or ectopic ureter (n = 1). Infants with infravesical obstruction or refluxing systems were excluded. All infants had a normal renal function and probably only 5 of them (23%) would have been diagnosed during infancy without prenatal diagnosis. A total number of 26 renal units was evaluated. Six infants had ipsilateral duplication with additional contralateral duplication (n = 2) or vesicoureteric reflux (n = 2). A nonfunctioning kidney or upper pole of duplication was noted in 7 units (5 with ureteroceles); in two instances a moderately dysplastic kidney was present. One boy with urinary infections developed renal scarring during follow-up. Conservative treatment was performed in 14 renal units while 12 units of 11 children had 22 operations (9 temporary diversions) at a mean age of 4,6 months. A severe operative complication was noted in one infant. Conservative treatment is justified in many infants with primary obstructive megaureters but severe renal dysplasia may be present even neonatally. Yet we feel that prenatal diagnosis benefitted most infants, especially those with the most severe malformations.


Invisible cardia cancer metastasis to the diaphragm.

The best surgical procedure to treat a carcinoma in the gastric cardia remains a controversy because the carcinoma is often advanced and there are other unknown factors. In this article the incidence of invisible metastasis from cardia cancer to the diaphragm will be analyzed using an experimental cardia cancer model and clinical studies. An experimental cardia cancer was induced by an endoscopic injection of VX2 cancer cells into the submucosal layer of the esophago-gastric junction in rabbits using a 27G needle and an Olympus BF-4B2 bronchofiberscope. A total of 26 cardia cancer models for Borrmann type 2 or 3 were produced. Of these, six (23%) had visible cancer metastases in the diaphragm, including 4 cases with direct invasion and 2 cases with peritoneal dissemination on the surface of the diaphragm. Four (20%) of the remaining 20 were histologically found to have macroscopically-invisible cancer metastases mainly in the lymph vessels of the left hemidiaphragm. From 1985 to 1988, 22 clinical cases of cardia cancer were managed by a combined total gastrectomy with a partial diaphragm resection through a left thoracoabdominal approach. When widely resected, reconstruction was performed using a latissimus dorsi muscle flap. Six (27%) of these 22 were also histologically found to have macroscopically-invisible cancer metastases to the diaphragm, including 1 (11%) of the 9 well-differentiated type and 5 (39%) of 13 poorly-differentiated type adenocarcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)


Retrospective studies of gastric subserosal (ss) cancer--in comparison to pm- and se-cancers.

The deepest gastric cancer invasion into the tela subserosa is expressed as the ss-cancer. Subserosal gastric cancers (ss) can be divided into 4 subtypes; ss alpha, ss beta, (ss gamma) and ss gamma, pathologically. These four subtypes were compared to cancerous invasion into the muscularis propria (pm-cancer) and cancerous invasion with serosal exposure (se-cancer). During the 10 years from 1979 to 1988, a total of 938 cases with gastric cancer were resected in the First Department of Surgery, Kurume University Hospital. Of these, 104 (11.1%) cases were ss-cancers, consisting of 28 (27%) cases of ss alpha, 33 (32%) cases of ss beta, 4 (3%) cases of (ss gamma) and 39 (38%) cases of ss gamma. Pm-cancers and ss-cancers were most frequently observed in Borrmann type 2, macroscopically, and in the differentiated type, histologically. On the other hand, se-cancers were frequently observed in Borrmann type 3 and in an undifferentiated type. Positive lymph node metastases were found in 49.1% of pm-cancers, in 50.0% of ss-cancers and in 79.9% of se-cancers (p < 0.01), with no statistical difference in the positive lymph node metastasis rates for the subdivisions of ss-cancer. In ss-cancer, however, there was a statistical difference in prognosis according to the tumor size, and according to the degree of subserosal infiltration. The 5-year survival rate was 82.3% for pm-cancer, 75.0% for ss-cancer and 34.7% for se-cancer (p < 0.01).


Gastric cancer surgery in the elderly.

Although there is a decreasing number of gastric cancer patients in Japan, the number of patients over 80 years of age is increasing. Forty patients over 80 years of age (from 80 to 88 years) with gastric cancer (Group 1) during the 10 years from 1980 to 1989 were retrospectively investigated and compared with those 70-79 years of age (Group 2). The resectability rate was 80% in Group 1 and 89% in Group 2. Early gastric cancer was observed at a rate of only 25% in Group 1 and 39% in Group 2. Pathologically, the differentiated type occurred in 78% of those in Group 1 and 68% of Group 2. Total gastrectomy was performed in only 6% of the resected cases in Group 1 and in 25% of Group 2. A combined resection including such operations as pancreatico-splenectomy or splenectomy (PS) was employed in none of the total gastrectomy cases in Group 1 and in 30% of Group 2. R3 gastrectomy was performed in none of the patients in Group 1 and in 21% of those in Group 2. Postoperative complications occurred in 25% of Group 1 patients and in 12% of Group 2 patients. Anastomotic leakage occurred in 3% of those in Group 1 and in 4% of those in Group 2. The 5-year survival rate was 47% for all the resected cases in Group 1 and 68% for Group 2. The 5-year survival rate was 61% for those who underwent a curative (radical) gastrectomy in Group 1, and 84% for those in Group 2.


[The anion gap--screening for hyperlactatemia in critically ill children?].

Serum lactate provides important information about tissue perfusion in critically ill patients. Aim of this study is to evaluate anion gap as a screening method to detect hyperlactatemia at a pediatric intensive care unit. In infants and children of different ages and diagnosis we determined blood gases, electrolytes and lactate. Sensitivity of anion gap was increasing with increasing hyperlactatemia. For the total population the test exhibited a sensitivity of 64% and a specificity of 76%, respectively. The power of anion gap as a screening method to detect hyperlactatemia was similarly fair for all age groups. Therefore hyperlactatemia has also to be included in the differential diagnosis of non-anion gap metabolic acidosis.


Beta protein precursor expression in human platelets and a megakaryocyte cell line. Possible implications for the origin of cerebral amyloidosis in Alzheimer's disease.

The origin of the amyloid beta protein (A beta) that is the main constituent of amyloid fibrils occurring in the senile plaques and cerebrovasculature of individuals afflicted with Alzheimer's Disease, Down's Syndrome, Hereditary Cerebral Hemorrhage with Amyloidosis--Dutch Type, and Sporadic Cerebral Amyloid Angiopathy, is central to the pathogenesis of these disorders. Evidence exists to support a neuronal and/or a vascular origin. We have reported that platelets may serve as one possible source of the A beta sequence via an intact, membrane-associated Beta Protein Precursor (beta PP) which is encoded by a platelet transcript (BBRC 173:1292-1298, 1990). Immunoaffinity chromatography and western blotting of extracted cellular proteins, polymerase chain reaction amplification of beta PP mRNA, fluorescence activated flow cytometric analysis, and confocal scanning laser microscopy have been employed to characterize the presence and distribution of thrombocytic beta PP. Immunoblot analysis with antibodies specific for the carboxyl-terminal end of beta PP indicates that platelets and the Dami megakaryocyte cell line express membrane-associated species of intact beta PP ranging in molecular weight from 110 to 140 kilodaltons (kd), as well as carboxyl-terminal reactive forms ranging from 16 to 22 kd. Thrombin stimulation of platelets induces the release of five soluble beta PP species, which possess apparent isofocusing points in the range of 4.1-5.5. By contrast, extracts of peripheral blood mononuclear cells enriched by ficoll centrifugation, endothelial cells and a B cell line were not immunoreactive by western blot, even though beta PP transcripts could be amplified by polymerase chain reaction. The distribution of platelet beta PP was localized by flow cytometric analysis and scanning laser microscopy, using fluorescein-labeled antibodies. Study of the subcellular distribution of platelet beta PP indicates that these translation products are accumulated in discrete foci throughout the thrombocyte, possibly corresponding to secretory granules. The size of the carboxyl-terminal forms of beta PP indicate that the A beta sequence is present as a membrane associated constituent in unstimulated platelets, and may represent alternative pathways of beta PP processing. Cleavage or other abnormal processing of platelet-associated beta PP in Alzheimer's disease provides one mechanism whereby cerebral amyloid might derive from the circulation.


Cellular tropism and localization in the rodent nervous system of a neuropathogenic variant of Friend murine leukemia virus.

We studied PVC-211 murine leukemia virus (MuLV) (1), a neuropathogenic variant of Friend MuLV, to determine its cellular tropism and distribution in the nervous system of infected rats and the factors that affected disease expression. Rats from five different strains and mice from 3 strains were inoculated intracerebrally or intraperitoneally from birth to 10 days of age and observed for signs of neurologic disease and tumors for 24 weeks. Nervous system pathology, MuLV gp70 expression, and virus production were evaluated weekly for 4 weeks after perinatal infection of Fisher (F344) rats. Blood-brain-barrier integrity and ultrastructure were evaluated in 21-day-old symptomatic infected rats. Microvessel and mixed glial cell cultures were prepared from brains of infected and uninfected 21-day-old F344 rats and evaluated for virus production, MuLV gp70 expression, and the presence of PVC-211 MuLV DNA. Tremor, ataxia, spasticity, and hindlimb weakness occurred in rats and mice as early as 3 weeks after neonatal infection. Severity, latency, and progression varied among mouse and rat strains but exposure to PVC-211 MuLV before 6 days of age was required for disease expression. Rapid PVC-211 MuLV replication in brain capillary endothelial cells (BCEC) early in the perinatal period was followed by widespread astrogliosis, neuropil vacuolation, and finally, neuronal degeneration in the spinal cord, brainstem, cerebellum, and subcortex. MuLV gp70 expression in vivo increased during infection, was restricted to BCEC, but was not associated with perivascular inflammatory infiltrates. BCEC cultured from microvessel preparations but not astrocytes or microglia in mixed glial cell cultures isolated from infected rats contained PVC-211 MuLV DNA, expressed MuLV gp70, and produced infectious virus. The rapid replication of PVC-211 MuLV that occurs in the nervous system of infected rodents is restricted to BCEC. These infected BCEC appear to play a critical role in initiating the astroglial response in this neurodegenerative process through mechanisms that remain to be defined.


Myocardial heterogeneity and regional variations in response to injury.

Different regional variations in the heart with respect to structure, function, and metabolism are known. However, regional heterogeneity with respect to histochemical localization of enzymes under normal as well as different pathologic conditions remain to be described. Histochemical localization of glycolytic, oxidative, and hydrolytic enzymes was done in right and left ventricles, atria, nodal tissue, and Purkinje system in isolated perfused rat hearts under control as well as different experimental conditions including calcium paradox, ischemia-reperfusion and oxygen-free radicals. Histochemical reaction for glycolytic enzyme glycogen phosphorylase as well as for acetylcholine esterase was more intense in the nodal tissue and Purkinje fibers, whereas oxidative enzymes showed intense reaction in the contractile cells of the ventricles. Calcium paradox caused more histochemical enzyme changes in the subepicardial layer. Ischemia reperfusion had more damaging effect in the subendocardial layer. Oxygen-free radicals caused transmurally focal injuries. This pattern of histochemical changes also correlated with ultrastructural injury in these regions. Ventricular muscle suffered marked decreases, whereas atrial muscle showed a relatively less decrease in different histochemical enzyme activities. Purkinje fibers were the least affected tissue in this respect. The differential changes were most sensitively reflected by glycogen phosphorylase followed by lactate dehydrogenase, alkaline phosphatase, isocitrate dehydrogenase and beta-hydroxybutyric dehydrogenase. Regional heterogeneity with respect to histochemical distribution of enzymes in a normal heart may have contributed to unique regional responses to different injuries, whereas transmural inhomogeneity in the ventricular response may have to do with the functional and/or metabolic transmural differences.


Arteriopathy in macaques infected with simian immunodeficiency virus.

An arteriopathy characterized by intimal and medial thickening and fibrosis was seen in 19 of 85 rhesus monkeys infected with simian immunodeficiency virus (SIV), a lentivirus with morphologic, genetic, and biologic similarities to HIV-1 and HIV-2. All cases of simian AIDS in rhesus monkeys at the New England Regional Primate Research Center, resulting from either experimental or naturally acquired SIV infection, were retrospectively examined for evidence of histopathologic changes to the vasculature. Of the 85 SIV-related deaths recorded in the pathology files to date, tissues from 19 animals were chosen for further study because of thickening, disruption, inflammation, or other abnormality to any layer of the vascular wall. The lesion was characterized by special stains, immunoperoxidase procedures, and ultrastructural examination. Affected monkeys of both sexes varied in age from 4 months to 17 years at the time of inoculation and survived from 41 days to 4 years after infection. Pulmonary arteries were affected in all 19 animals, while vessels in other parenchymal organs were involved less frequently. In addition to sometimes marked intimal thickening with luminal occlusion, the internal elastic laminae were fragmented and interrupted. Seven of 19 animals had pulmonary thromboses with varying degrees of organization and recanalization. Immunohistochemical studies, special stains, and ultrastructural analyses revealed the thickened intimae to be composed predominantly of collagen, extracellular matrix, and smooth muscle cells. Ultrastructurally, endothelial cells from both early (no intimal thickening) and advanced lesions were plump, vacuolated, and often disorganized and detached from the subendothelial space. Increased numbers of macrophages (CD68+) were found in the adventitia and occasionally in the thickened intima and media. Rare, fully differentiated macrophages (CD68+, 25F9+) were demonstrated in lumina of affected vessels, some of which expressed p27 SIV gag protein. However, the lesion was not uniformly associated with localization of either viral protein or RNA at the site using immunohistochemistry or in situ hybridization, respectively. A similar arterial lesion has been described in children with AIDS. The morphologic findings in macaques and their similarity to arteriosclerotic changes induced by experimental endothelial damage in other species collectively suggest that arteriopathy in AIDS may represent a manifestation secondary to primary endothelial injury.


Transforming growth factor-beta regulates increased ductus arteriosus endothelial glycosaminoglycan synthesis and a post-transcriptional mechanism controls increased smooth muscle fibronectin, features associated with intimal proliferation.

In previous studies we established that there are developmentally regulated increases in endothelial hyaluronan (HA) and heparan sulfate (HS), and smooth muscle cell fibronectin (FN) related to the formation of intimal cushions, structures essential to the postnatal closure of the ductus arteriosus (DA). In this report, we investigated the mechanisms underlying these features to ascertain whether they were independently or coordinately regulated. We determined by assessing HA polymer size and by pulse labeling with [3H]glucosamine whether the increased glycosaminoglycans (GAGs) incorporated in DA compared with aorta (Ao) endothelial cell matrices reflected increased synthesis of HA and HS rather than decreased degradation. We assessed whether transforming growth factor-beta (TGF-beta) may be responsible for the increased DA endothelial GAGs and smooth muscle FN production by confirming the presence of TGF-beta in DA tissue using immunohistochemistry and by assessing the effect of adding neutralizing antibodies to the cell cultures. We next determined whether the level of regulation of the increase in FN in DA smooth muscle cells was transcriptional or post-transcriptional by relating protein synthesis to steady state mRNA levels and to mRNA levels after serum stimulation. Using northern blot analyses with specific probes, we also explored the possibility that the FN produced by the DA and Ao was qualitatively different in the proportion of isoforms containing the V95+ region associated with secretion or the EIIIB+ region that has been related to migration. We observed that HA polymer size produced by DA and Ao endothelial cells was similar and we further verified using pulse labeling that the increase in DA compared with Ao endothelial GAGs reflected increased synthesis of HA and HS rather than decreased degradation. There was increased immunostaining for TGF-beta in DA compared with Ao tissue and we showed that TGF-beta neutralizing antibodies reduced synthesis of GAGs by the DA endothelial cells to the level of that seen in the Ao cells, but did not reduce DA smooth muscle cell FN synthesis. The increase in FN synthesis by DA compared to Ao smooth muscle cells was not associated with increased levels of steady-state mRNA for FN. Furthermore, following serum-stimulated increases in FN mRNA, the DA yielded greater amounts of FN protein compared to Ao smooth muscle cells. The increased FN production by the DA smooth muscle cells could not be attributed to a relative lack of degradation of FN protein or mRNA, or to qualitative differences which might influence secretion, as both cell types contained similar proportions of EIIIB+ and V95+ isoforms of FN. These results would suggest that, in contrast to the TGF-beta dependent increase in DA endothelial GAG synthesis, the increase in DA smooth muscle FN synthesis arises through differences in post-transcriptional regulation that are likely independent of TGF-beta.


Immunomorphometric studies of proteinuria in individual nephrons of rats.

Heterogeneity of proteinuria among nephrons has been directly shown by micropuncture analysis of experimental models. Since the number of nephrons per kidney that are accessible for micropuncture is very small, we have developed a new immunomorphometric method for directly studying proteinuria in a much larger number of individual nephrons. This new method is based on the luminal surfaces of thick ascending limb of the loop of Henle (TAL) cells collectively functioning as an immunoabsorbent column for anti-Tamm-Horsfall protein antibodies that enter the urinary filtrate of that nephron. The distribution of luminal IgG deposits formed in TALs after injection of anti-Tamm-Horsfall protein antibodies was studied in three models of experimental proteinuria in rats to define the relationship between the formation of luminal deposits and the overall level of albuminuria and to test the utility of this method in analyzing the heterogeneity of luminal deposits among nephrons in other models. A close relationship between the magnitude of albuminuria and the distances that luminal IgG deposits extended along the straight course of TALs in individual nephrons of rats injected with rabbit anti-Tamm-Horsfall protein antibodies was established in a model of proteinuria with a uniform pattern of glomerular hemodynamics, heterologous immune complex nephropathy in rats. In models with more heterogeneous glomerular hemodynamics, autologous immune complex nephropathy and aminonucleoside nephrosis, greater heterogeneity in luminal IgG deposit formation among nephrons was demonstrated. The distances that luminal IgG deposits extended along TALs was more variable in these models than in heterologous immune complex nephropathy rats with comparable levels of albuminuria. Variability in the distances that luminal IgG deposits extend along TALs reflects heterogeneity among nephrons. The luminal deposit technique provides a new means for direct analysis of variability of dysfunction in many individual nephrons not accessible to micropuncture.


Chromogranin A, chromogranin B and secretogranin II mRNAs in the pituitary and adrenal glands of various mammals. Regulation of chromogranin A, chromogranin B and secretogranin II mRNA levels by estrogen.

The chromogranin/secretogranin (Cg/Sg) acidic proteins are widely distributed in vertebrate species. They are thought to play a role in hormone packaging within secretory granules, in hormone secretion, and serve as prohormones for various proteolytic cleavage products. The genes for most members of the Cg/Sg family have been cloned, so hybridization analysis can be used to analyze the distribution and regulation of Cg/Sg mRNAs in various vertebrate species. The method of in situ hybridization was used to localize chromogranin A, chromogranin B, and secretogranin II in adrenal and pituitary tissues from laboratory animals and from humans in order to analyze the distribution of various Cg/Sg mRNAs in these tissues. To gain some insight into the regulation and possible functions of specific Cg/Sg members, female rats were ovariectomized for different periods with and without estrogen replacement and the pituitaries were subsequently analyzed by in situ hybridization and Northern hybridization analyses. Combined ISH and immunohistochemistry were used to localize the specific cell types in normal rat pituitary that expressed the mRNA for chromogranin A, chromogranin B, and secretogranin II. All three Cg/Sg mRNAs were detected in pituitary and adrenal tissues of rats, mice, dogs, monkeys, and humans. Combined in situ hybridization and immunohistochemistry using rat pituitary revealed that the glycoprotein hormone-secreting cells expressed all three Cg/Sg mRNAs in approximately equal amounts. Ovariectomy followed by estrogen replacement resulted in decreased levels of CgA and SgII mRNAs. In contrast, the level of CgB mRNA, that was not changed by ovariectomy, was increased after estrogen treatment, probably secondary to prolactin cell hyperplasia. The three principal Cg/Sg mRNAs are present in the adrenal and pituitary of various vertebrates. Estrogen plays a significant role in regulating the mRNA levels of different Cgs/Sgs suggesting functional and regulatory differences in Cg/Sg proteins.


Blindness in South Carolina.

In less than 40 years the number of people aged 55 and older will constitute almost a third of the United States population. With the median age in South Carolina increasing, the incidence of visual impairment and blindness will rise. Most of the leading causes of blindness in South Carolina are age related. Most of these causes can be prevented or treated resulting in the preservation of functional vision. By increasing public awareness of blindness prevention opportunities, a significant reduction in blindness in South Carolina can be attained. By eliciting the help of all health professions in South Carolina the incidence of visual impairment/blindness can be reduced.


Aging Koreans' perceived conflicts in relationships with their offspring as a function of age, gender, cohabitation status, and marital status.

The Youn Scale was used to assess aging Koreans' perceived conflicts in relationships with their adult offspring. The sample consisted of 623 elderly Koreans between the ages of 55 and 84 years. Results indicated that aging Koreans experienced significantly more conflicts in their relationships as they grew older. There were also differences in the perceptions of problems in relationships with their offspring between those who lived together with their adult children and the those who did not, and also between those who were married and those who were single. The findings imply that aging Koreans want to have qualitatively better (i.e., warmer and closer) relationships with their offspring, regardless of their bereavement status and cohabitation status.


Gender and self-disclosure revisited: personal and contextual variations in self-disclosure to same-sex acquaintances.

Male and female American students who differed in masculinity and in femininity self-disclosed to a same-sex stranger in contexts that made either social/expressive motives or instrumental motives salient. The results were consistent with the primary assertion that measures of sex role identity are better predictors of contextual variations in self-disclosure than is sex per se. Sex consistently failed to predict subjects' willingness to self-disclose, both within and across contexts, whereas femininity promoted self-disclosure in the context that was clearly social and expressive in character. Although masculinity failed to exert the expected facilitative impact on self-disclosure within the instrumental context, it nonetheless influenced the results; androgynous subjects, who scored high in both masculinity and femininity, were more self-revealing across contexts than was any other group.


Environmental concern and cooperative-competitive behavior in a simulated commons dilemma.

Commons-dilemma simulation games are designed to examine behavior associated with preservation and destruction of slowly regenerating natural resources. In Experiment 1, 120 introductory psychology students in the United States were assigned to high- or low-environmental-concern conditions based on a median split of their scores from a pretest. They then played either a points game, in which they selected numerical points from a slowly regenerating pool, or a tree game, in which they harvested trees from a jointly managed forest. After the game, subjects were asked to sign a petition for an environmental cause, to participate in a litter pick-up, and to participate in a recycling drive. Neither environmental concern nor proenvironmental behaviors were related to commons dilemma performance. In Experiment 2, 57 other introductory psychology students were assessed on environmental concern and Machiavellian personality, size of other players' harvesting choices, and other players' altruistic choices, all correlated with subjects' outcomes in the game. Overall, cooperation and competition were more important than environmental concern in predicting behavior in the commons dilemma simulation game.


Cognitive profiles of Japanese and Canadian kindergarten and first-grade children.

Japanese kindergarten and first-grade children were given the Canadian Cognitive Abilities Test (CCAT), with slight cultural modifications. Widely used in Canadian and American schools, the CCAT consists of three batteries: verbal, quantitative, and nonverbal. The sample consisted of 454 Japanese children (234 boys, 220 girls). Results were examined by 3-month age intervals (chronological age range, 60 to 87 months of age). Subjects' scores were compared with CCAT norms, based on the performance of 3,500 Canadian children at each age level. On each battery, the Japanese children outperformed their Canadian counterparts, but the differential was most apparent on the verbal battery. Moreover, on the nonverbal battery for kindergarten Japanese children (ages 60 to 72 months), significant differences appeared only with the 60- to 63-month age cohort. Results indicate that the higher achievement of Japanese children was apparent by the time they entered kindergarten and that higher Japanese educational productivity could not be solely attributed to schooling effects. Furthermore, the data indicate that the early academic advantage of Japanese children may widen as they progress through their first year of school. (Longitudinal replication studies are suggested for examination of the long-range impact of the early cognitive advantage of Japanese children.)


Evaluation of a rapist as a function of expressed intent and remorse.

Two studies were conducted to examine the effects of expressed versus denied intent and remorse on evaluation of a rapist. In both studies, the rapist was evaluated more negatively and was assigned a longer prison sentence when expressing rather than denying intent. The rapist received more favorable evaluations when expressing rather than denying remorse. Manipulation of the rapist's expressed remorse did not significantly affect the recommended prison sentence. However, the recommended prison sentence did correlate significantly with participants' perceptions of the rapist's remorse. A multiple regression analysis indicated that recommended prison sentence could be best predicted by attributions of cause, intent, and remorse. The results were related to a growing body of research on accounting strategies, responsibility, and excuse making.


Quantitative description of the dysarthria in women with amyotrophic lateral sclerosis.

Speech intelligibility and its phonetic and acoustic correlates were studied in a group of 10 women with amyotrophic lateral sclerosis (ALS). Intelligibility assessment with a word-identification test indicated that the most disrupted phonetic features pertained to velopharyngeal valving, lingual function for consonant contrasts of place and manner, and syllable shape. An acoustic signature analysis based on trajectories of the first and second formants in selected monosyllabic test words revealed that the mean slope of the second formant (F2) was reduced compared with that of a normal geriatric control group. This F2 slope reduction is interpreted to reflect loss of lingual motoneurons. Acoustic measures of phonatory function for sustained vowel prolongation demonstrated abnormalities in fundamental frequency, perturbations of frequency (jitter) and amplitude (shimmer), and signal-to-noise ratio. The data for women with ALS are compared with data for a normal geriatric control group of women and with data for a group of 25 men with ALS (Kent et al., 1990). Although the overall ranking of errors was similar for males and females with ALS, men were more likely to have impairments of voicing in syllable-initial position.


The relationship of vallecular residue to oral involvement, reduced hyoid elevation, and epiglottic function.

The purpose of this investigation was to identify certain variables that may result in vallecular residue after swallowing. The relationship between vallecular residue and oral-stage dysphagia, reduced hyoid elevation, and movement of the epiglottis was assessed in 330 patients referred to the speech pathology section for evaluation of oropharyngeal swallowing function. Patients with vallecular residue were more likely to have oral involvement or deviant epiglottic function, characterized by an absence of epiglottic inversion or incomplete inversion, than patients without vallecular residue. Although the primary focus of the study was between vallecular residue and the other select variables, the interrelationships among the three other variables were also studied. Patients with deviant epiglottic function were more likely to have oral involvement, reduced hyoid elevation, or vallecular residue than patients without deviant epiglottic function and patients with reduced hyoid elevation were more likely to have oral involvement than those with normal hyoid elevation. Multivariate analysis revealed that the relationship between oral involvement and deviant epiglottic function, present in the bivariate analysis, was not significant when controlling for other relationships in the model. The relationship between primary medical diagnostic category and the presence/absence of vallecular residue as well as the other dichotomous variables varied between and within diagnostic categories.


Parent verbal interactions and speech rate: a case study in stuttering.

This single-case study of indirect stuttering treatment is intended to identify variables for further research. The study used post hoc analyses of changes in parent speech variables and changes in the child's stuttering. The analysis was conducted in two parts. Study I examined the relationships between the child's percent syllables stuttered and the parents' speech rates and percentages of nonaccepting statements, interruptions, questions, nonaccepting questions, and talk time. The only parent variable significantly correlated with the child's stuttering was the mother's speech rate. In Study II the child's percent syllables stuttered were subdivided into primary (effortless) and secondary (tense) stuttering. Each category was then correlated with the parent variables examined previously. Results suggested that the parent variables that were significantly related to the child's primary stuttering were not the same as those significantly related to her secondary stuttering. Specific parent variables are suggested for further study.


A longitudinal study of stuttering in children: a preliminary report.

The objectives of this pilot study were to establish methods for longitudinal research of stuttering in children and to provide preliminary data on the variations that occur in disfluencies during the developmental course of stuttering. Twenty-seven preschool-aged children were followed for a minimum of 2 years shortly after they began stuttering. Tape-recorded speech samples were obtained from the children at several intervals during this period. The number of various types of disfluencies was counted in the speech samples obtained in each testing period. Twenty-one children continued to be followed for varying periods of up to 12 years. Eighteen of the 27 subjects received a few speech treatment sessions during the initial period of the study, whereas 9 children did not receive direct treatment. Results indicated that for the two subgroups there was a marked deceleration over time in the mean frequency of stuttering-like disfluencies. Individual subjects' data showed considerable variability in the longitudinal development of disfluency but most subjects followed the patterns of the group means. Much of the reduction took place during the early stage of the disorder, especially near the end of the first year post-onset. There were indications that group differences between chronic and recovering stutterers become distinct by approximately 20 months post-onset.


Vocal tract steadiness: a measure of phonatory and upper airway motor control during phonation in dysarthria.

Acoustic analyses of upper airway and phonatory stability were conducted on samples of sustained phonation to evaluate the relation between laryngeal and articulomotor stability for 31 patients with dysarthria and 12 non-dysarthric control subjects. Significantly higher values were found for the variability in fundamental frequency and format frequency of patients who have Huntington's disease compared with normal subjects and patients with Parkinson's disease. No significant correlations were found between format frequency variability and the variability of the fundamental frequency for any subject group. These findings are discussed as they pertain to the relationship between phonatory and upper airway subsystems and the evaluation of vocal tract motor control impairments in dysarthria.


Locus equations as an index of coarticulation for place of articulation distinctions in children.

Locus equations were investigated as a phonetic index for children's production of stop + vowel tokens. Locus equations are straight-line regression fits to data points formed by plotting onsets of F2 transitions along the ordinate and their corresponding midvowel nuclei along the abscissa. Such functions for adult speech have been found to be extremely linear with slope and y-intercept values contrastively distinctive across place of articulation. Sixteen children, aged 3-5 years, produced /bVt/, /dVt/, and /gVt/ tokens embedded in a carrier phrase and repeated in randomized order a minimum of three times. Six medial vowel contexts were used [i, I, ae, [symbol: see text], a, u]. Both individual and group mean scatterplots were extremely linear and highly remniscent of adult prototypes. While labial and velar slopes exhibited some degree of overlap, labial versus alveolar and alveolar versus velar slopes were significantly different. All y-intercepts as a function of place of articulation were significantly different. Compared to adult norms, intersubject variability of slope and y-intercept ranges were greater for children. Locus equations can provide a phonetic descriptor for a child's attainment of stop place categories seeking to achieve the adult standard of a balance between coarticulatory adjustments and contrastive distinctiveness.


Onset of stuttering in preschool children: selected factors.

This investigation provides updated information on the onset of stuttering, explores variations in the onset, and studies possible relationship of stuttering onset to the factors of age, gender, familial history, severity, and stress. Data were obtained for 87 preschool children through parent interviews, using a standardized questionnaire. Interviews were conducted within 12 months after the disorder was first diagnosed. Results for selected items indicated that onset tended to occur at an earlier age than was previously thought and was sudden and/or severe in a substantial number of cases. Physical or emotional stress and familial histories of stuttering were reported for many of the participating children. A significant gender factor was found. About twice as many boys as girls stuttered and girls began stuttering at a significantly earlier age. There was a positive relationship between severe stuttering and sudden onset. Several other tendencies for relationship between factors were either weak or not significant for the present sample size. The findings are discussed with special reference to the possible relationship between stuttering onset and maturational processes and the possible contribution of data on onset to the differentiation of stutterers.


The relationship between communication attitude, anxiety, and depression in stutterers and nonstutterers.

People who stutter are frequently viewed as more anxious than nonstutterers and as being depressed. Further, a strong and pervasive stereotype is held by nonstutterers that people who stutter are guarded, nervous, and tense. This study examined self-perceptions of general state and trait anxiety, depression, and communication attitude in matched groups of stutterers and nonstutterers. Results refute the assertion that people who stutter are more anxious or depressed than those who do not. Anxiety and depression are not related to self-ratings of stuttering severity. Communication attitude is negative for this group of people who stutter and becomes increasingly negative as self-ratings of stuttering become more severe. People who stutter, grouped by severity rating, differed in the strength of the relation between measures of communication attitude, anxiety, and depression. Findings suggest that the anxiety of people who stutter is restricted to their attitude towards communication situations and that it is a rational response to negative communication experiences.


Constancy of interstress intervals in the fluent speech of people who stutter during adaptation trials.

The constancy of interstress intervals (ISIs) was studied in the fluent speech of 2 people who stutter during five adaptation trials. Counter to prediction, ISI constancy did not improve as an accompaniment to the reduction of stuttering from Readings 1-5. Overall, the subjects' ISIs were substantially more variable in duration than those of 2 nonstutterers. This was accounted for by the subjects' unusually long ISIs in utterances that placed greater demands on speech motor control processes. Implications for impairment source factors in stuttering are discussed.


Factors underlying neuropsychological test performance in chronic severe traumatic brain injury.

The neuropsychological test performance of subjects with traumatic brain injury (TBI) of the closed head type was investigated using a test battery consisting of traditional clinical instruments with expanded language measures. TBI subjects were specifically selected to include only those with a pattern of predominantly diffuse cerebral injury to allow conclusions regarding language performance in the absence of focal aphasia-producing lesions. Factor analysis of the test scores resulted in the extraction of three interpretable factors associated with performance on this battery: perceptual, general language, and mental efficiency. The results were compared to those obtained in previous factor-analytic studies of brain-damaged subjects, revealing patterns for the language/verbal subtests that diverged from those observed formerly. Two explanations are considered for these findings, the first interpretation centering on the notion of select impairments to specific cognitive processes and the second relating to impairments in the capacity to allocate resources effectively.


Residual effects of preschool phonology disorders in grade school, adolescence, and adulthood.

This study used a cross-sectional design to examine the performance of people with a history of a preschool phonology disorder on measures of phonology, reading, and spelling at preschool age (n = 20), grade school age (n = 23), adolescence (n = 17), and adulthood (n = 17). Results showed that at each age group, subjects with a history of a disorder performed more poorly than control subjects matched for age, sex, and socioeconomic status in all domains. Comparisons across each successive age group revealed a higher performance on measures from preschool to grade school age, and a smaller but steady improvement from grade school age to adolescence to adulthood. Subjects with a history of other language problems, in addition to the phonology disorder overall, performed more poorly than subjects with a history of a preschool phonology disorder alone on the reading and spelling measures. These findings suggest that remnants of a preschool phonology disorder are detectable past grade school age and into adulthood.


Diagnosing specific language impairment in adults for the purpose of pedigree analysis.

Two sets of diagnostic measures were administered to a group of 35 adults with well-documented histories of specific language impairment and to a control group of 35 normal language users. These measures involved the comprehension and production of words and sentences in formal and spontaneous speaking activities as well as measures of verbal memory and auditory temporal perceptual ability. One set of tasks was administered in a standard face-to-face setting and the other set was given over the telephone. Multivariate and univariate tests indicated that the adults with a history of specific language impairment performed more poorly on all tasks administered. A discriminant analysis of the two sets of measures indicated that four measures in each set identified language-impaired individuals with 97% accuracy for the face-to-face battery and 95% accuracy for the telephone battery. These results suggest that it should be possible to diagnose specific language impairment in the adult family members of children with specific language impairment and therefore permit accurate construction of pedigrees for specific language impairment.


Message-encoding techniques for augmentative communication systems: the recall performances of adults with severe speech impairments.

This study investigated the cognitive and linguistic processing demands of message-encoding techniques used to retrieve prestored messages from computer-based augmentative communication systems. Twelve physically disabled adults with severe speech impairments participated in six counterbalanced experimental conditions, consisting of three encoding techniques (salient letter, letter category, and iconic codes), each in a personalized condition in which subjects selected their own codes and in a nonpersonalized condition in which codes were preselected by a clinician. In each of the experimental conditions, the subjects participated in five learning and testing sessions. During these sessions, the subjects learned the codes for lists of 80 messages, half of which involved concrete referents and half abstract concepts. Results indicated that the subjects were more accurate in recalling the codes to retrieve preprogrammed messages when using the two letter encoding techniques than when using the iconic technique. No reliable differences were found between recall performances with personalized codes and with nonpersonalized ones for any of the three encoding techniques. Code recall improved consistently across the series of learning sessions; there were no significant differences in the rates of learning across the encoding techniques. Subjects were found to be more accurate at recalling the codes to retrieve concrete messages than those to retrieve abstract messages.


Instructing facilitators to support the communication of people who use augmentative communication systems.

A single-subject multiple-baseline design, replicated across three dyads, was used to examine the efficacy of instructing facilitators (i.e, significant others) to promote communication with people who use augmentative and alternative communication (AAC) systems. Facilitators were instructed in four 1-hour sessions to decrease their conversational control and provide more opportunities for the participants using AAC systems to communicate. Following instruction, facilitators decreased their rates of turn-taking and initiations and increased the proportion of turns that were responsive. Participants using AAC systems increased the frequency of their initiations. Following intervention, turn-taking and initiation patterns in the dyads were more reciprocal. Generalization occurred to the natural environment. Results suggest that facilitator instruction is an effective and efficient means of promoting greater participation in daily interactions by people who use AAC systems.


Sources of variability in speechreading sentences: a generalizability analysis.

Generalizability theory (Cronbach, Gleser, Nanda, & Rajaratnam, 1972) was used to estimate the percentage of variance explained by three sources of variability in speechreading sentences: the subject, the talker, and the sentence materials. Videodisc recordings of the 100 CID Everyday Sentences (Davis & Silverman, 1970), spoken by a male and a female talker, were presented to 104 subjects with normal hearing. For performance on individual sentences (total number of words correct), the most important systematic sources of variability were the sentence (26.3%), the speechreader (10.5%), the talker (4.9%), and the interaction of talker and sentence (5.1%). Residual error accounted for 51.2% of the variance. Generalizability functions are presented, as a function of test length, for five models of test administration and interpretation. For 10-, 50-, and 100-item lists, generalizability is predicted to be .70, .92, and .96, respectively, for a single talker. Psychometric characteristics of these recordings of the CID sentences are also presented.


Age-related differences in processing dynamic information to identify vowel quality.

This study examined age-related differences in the use of dynamic acoustic information (in the form of formant transitions) to identify vowel quality in CVCs. Two versions of 61 naturally produced, commonly occurring, monosyllabic English words were created: a control version (the unmodified whole word) and a silent-center version (in which approximately 62% of the medial vowel was replaced by silence). A group of normal-hearing young adults (19-25 years old) and older adults (61-75 years old) identified these tokens. The older subjects were found to be significantly worse than the younger subjects at identifying the medial vowel and the initial and final consonants in the silent-center condition. These results support the hypothesis of an age-related decrement in the ability to process dynamic perceptual cues in the perception of vowel quality.


The clinical utility of the P3 AERP in children with auditory processing disorders.

This study investigated whether the P3 AERP could be used to reflect behavioral changes resulting from therapeutic intervention in a group of children with central auditory processing disorders (CAPDs). Results showed a significant decrease in P3 latency, along with a significant increase in P3 amplitude, following a structured treatment program. No changes occurred in either the CAPD control group or in the normal control group. These results suggest that the P3 AERP latency and amplitude measures are sensitive to changes in clinical status following a treatment program.


Performance over time of congenitally deaf and postlingually deafened children using a multichannel cochlear implant.

The speech perception performance of 10 congenitally deaf and 3 postlingually deafened children who received the Cochlear Corporation multichannel cochlear implant was examined and compared. The children were tested preimplant and at 6-month intervals up to 2 years using the Monosyllable-Trochee-Spondee test (MTS), the Word Intelligibility by Picture Identification test (WIPI), and Phonetically Balanced Kindergarten (PB-K) or Northwestern University List 6 (NU-6) word lists. The postlingually deafened children exhibited significantly improved performance on open- and closed-set tests of word recognition after 6 months of implant use, a pattern similar to that of postlingually deafened adult implant users. In contrast, the congenitally deaf children did not exhibit measurably improved performance on speech perception tests until after 12 months or more of implant use. With as much as 18-24 months of use, however, some congenitally deaf children demonstrated limited open-set word recognition.


The development and cross-validation of a self-report inventory to assess pure-tone threshold hearing sensitivity.

Previous attempts to assess hearing loss by means of self-report survey items have shown only low to moderate correlations with actual audiometric measures, probably because these attempts used items with high face validity rather than laboratory-tested validity. Beginning with a pool of 108 items used with 384 individuals, we developed a self-report inventory (see Appendix) suitable for group testing or survey administration, which appears to have high correlation with pure-tone hearing thresholds. The inventory was then cross-validated against laboratory audiometric measures in a separate sample of 422 subjects. The resulting 12-item Hearing Screening Inventory (HSI) was shown to be reliable with an internal consistency coefficient (alpha) of 0.89 and test-retest stability coefficient of 0.88. The correlation between pure-tone hearing thresholds in the better ear and the HSI scores for the combined samples was r = 0.81. The correct classification rate for the HSI was 92.1% for a low fence of 25-dB hearing level and 93.4% for a high fence of 55-dB hearing level. A conversion equation with estimated variability is also provided for point estimates of pure-tone hearing thresholds from the HSI scores. A copy of the inventory and scoring procedure is appended to this report.


Some psychometric properties of the Test of Basic Auditory Capabilities (TBAC).

This study examined some psychometric properties of the Test of Basic Auditory Capabilities (TBAC). Two experiments are described that evaluate the psychometric functions and the test-retest reliability of the tests comprising the TBAC. The psychometric functions were established for young listeners with normal hearing and the test-retest reliability was evaluated both with young listeners with normal hearing and elderly listeners with hearing impairment. Results indicate that maximum scores on the TBAC are reached at presentation levels of at least 65-75 dB SPL. In addition, the reliability analyses indicate that the TBAC is a reliable measure for both young listeners with normal hearing and elderly listeners with hearing impairment when at least one practice test is given.


Equivalent ear canal volumes in children pre- and post-tympanostomy tube insertion.

Pre- and postoperative equivalent ear canal volume measures were obtained from a group of 334 children ranging in age from 6 weeks to 6.7 years. The purpose of the study was to develop volumetric guidelines for the determination of tympanostomy tube patency. For children 4 years and older, almost no ambiguity existed in making this determination accurately. For younger children, the pre- and postoperative distributions overlap. A criterion value of greater than or equal to 1.0 cm3 as an indicator of a tympanic membrane perforation appears to yield the lowest possible error rate. When both pre- and postoperative measures are available, a difference of greater than or equal to 0.4 cm3 can be used in conjunction with the absolute value to identify a patent tympanostomy tube.


Detection and recognition of stop consonants by normal-hearing and hearing-impaired listeners.

This study examined the possibility that hearing-impaired listeners, in addition to displaying poorer-than-normal recognition of speech presented in background noise, require a larger signal-to-noise ratio for the detection of the speech sounds. Psychometric functions for the detection and recognition of stop consonants were obtained from both normal-hearing and hearing-impaired listeners. Expressing the speech levels in terms of their short-term spectra, the detection of consonants for both subject groups occurred at the same signal-to-noise ratio. In contrast, the hearing-impaired listeners displayed poorer recognition performance than the normal-hearing listeners. These results imply that the higher signal-to-noise ratios required for a given level of recognition by some subjects with hearing loss are not due in part to a deficit in detection of the signals in the masking noise, but rather are due exclusively to a deficit in recognition.


Frequency-importance functions for words in high- and low-context sentences.

The relative importance and absolute contributions of various spectral regions to speech intelligibility under conditions of either neutral or predictable sentential context were examined. Specifically, the frequency-importance functions for a set of monosyllabic words embedded in a highly predictive sentence context versus a sentence with little predictive information were developed using Articulation Index (AI) methods. Forty-two young normal-hearing adults heard sentences presented at signal-to-noise ratios from -8 to +14 dB in a noise shaped to conform to the peak spectrum of the speech. Results indicated only slight differences in 1/3-octave importance functions due to differences in semantic context, although the crossovers differed by a constant 180 Hz. Methodological and theoretical aspects of parameter estimation in the AI model are discussed. The results suggest that semantic context, as defined by these conditions, may alter frequency-importance relationships in addition to the dynamic range over which intelligibility rises.


Accuracy of intramedullary alignment in total knee replacement.

The accuracy of a system of intramedullary alignment using 6 mm rods was assessed in 100 patients undergoing total knee replacements. Post-operative, full length weight-bearing X-rays were used; the mechanical axis from head was used as the reference axis. The method of calculating the errors produced by flexion and rotation of the limb in relation to the X-ray beam is described, the mean deviation from the mechanical axis in 100 cases being 0.67 degrees valgus with a standard deviation of 2.47 degrees. The maximum error was 6.68 degrees valgus and 4.62 degrees varus. The purpose of this study is twofold, first to assess the accuracy of this system of intramedullary alignment and, second, to develop a method of correcting for apparent radiological misalignment using standard radiographic equipment.


An experimental apparatus for the simulation of three-dimensional movements in orthodontics.

An apparatus for the study of three-dimensional force systems and the resulting movements during orthodontic treatment is presented. The instrument consists of two force-torque transducers which are capable of recording both forces and torques simultaneously, in all spatial directions. Each sensor has a measuring range of 15N (450 Nmm) and a resolution of 0.02 N (0.5 Nmm) and is mounted on a set of three translational and three rotational stages driven by stepping motors. Positioning accuracy is in the range of 1 micron and 0.01 degrees respectively. The apparatus is computer controlled and supported by comprehensive software.


Aseptic loosening of the femoral component in cemented total hip replacement.

The purpose of this study was to identify factors which predispose to aseptic loosening of the femoral component in cemented total hip replacement. Its design was based on rigid selection criteria, so that successful and loose replacements which employed the same surgical technique were compared. Measurements of patient anatomy and of the insertion of the femoral component were made, by an accurate computer technique, on initial post-operative radiographs. Loosening was associated with heavier patients with a wider medullary canal which was flared proximally. This difference in anatomy led to differing distributions of cement in the successful and loose replacements. Medial cement-bone demarcation, at the mid-stem level, was also associated with loosening. These findings indicate the importance of optimizing the size of the prosthesis with respect to the femoral morphology.


Oxygen exchange mechanisms in the human placenta: mathematical modelling and simulation.

An exact knowledge of the human fetus's respiratory mechanisms is still lacking; in particular, the role of human placental anatomy in oxygen exchange has not yet been studied satisfactorily. In this paper, a mathematical model of placenta as O2 exchanger between maternal and fetal blood was developed; it led to the solution of equations based upon diffusion laws and the haemoglobin dissociation curve. Particular care was taken to represent the regimen of laminar motion or whirling into the capillaries. Theoretical results were compared, under physiological conditions, with clinical data relating to fetal oxygenated blood p O2 during the second half of gestation (20th-38th weeks), and a theoretical confirmation of the decreasing effectiveness of placental O2 exchange during gestation was found. The result was able to describe oxygen exchange during a period in which clinical data are scanty (23rd-30th weeks). The effects of some pathological events on O2 exchange were then simulated. Model parameters were changed to simulate the effects on oxygen exchange of some typical pathological variations of placental anatomical features: exchange surface thickness and capillary length. The curves obtained for different gestational ages can easily be correlated with echographic measures of placental volume and dimensions of placental capillaries. The results also show that the human placenta is more sensitive to pathologies when it is young than at term of gestation.


Pulse transmission and impedance characteristics of a non-uniform circulatory model.

In recent years, the technique of non-uniform transmission lines has been utilized in the synthesis of lines feeding antennae from transmitters, thereby maintaining matching over a wide band of frequencies and with varying load. For this reason, an electrical model based on that technique stems from the resemblance between the two systems: in both the feeding medium is non-uniform, and it is necessary to maintain a good response over a wide range of frequencies. Our non-uniform transmission line model of the arterial system, introduced in an earlier publication, supplies comprehensive answers to many questions dealing with the research into this system. Whereas in our earlier model the ohmic resistance R was considered small and not considered in the calculations, it is included in the present study. We have calculated the variation of the input impedance with the frequency and distance from the source, the effect of occluded main branches, augmentation of the pressure wave, the relationship between body size and heart rate and the matching of impedances at large bifurcations. We found that our calculated results agree very well with the quantitative results measured by other investigators in the field.


Experimental results on the rewarming of a cryopreserved organ phantom in a UHF field.

We describe a UHF rewarming system which has been used to measure warming rates, and particularly the uniformity of warming on three orthogonal axes, in a rabbit kidney phantom 36 mm in diameter. The stabilizing effect is demonstrated of using an E-field directed along the temperature gradient (or normal to any surface of dielectric discontinuity). One hot spot remains unaccounted for. The average warming rates and power dissipation are related to the volumetric heat capacity of the phantom material at -30 degrees C.


Development of a digital adaptive control system for PO2 regulation in a membrane oxygenator.

Regulation of gas exchange in artificial lungs (oxygenators) during cardiopulmonary bypass is normally achieved by manual control of the gas composition and flow in response to intermittent sampling of the arterial partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2). Manual control often results in abnormal blood gases which have been implicated in patient morbidity as well as influencing perfusion safety. Fine control of PaO2 and PaCO2 may be achieved by a combination of an in-line blood gas monitoring system and a membrane type oxygenator which is automatically regulated. The overall dynamics of the oxygenation process and control system components are complex and have nonlinear, multivariable and time-varying characteristics. Consequently, an adaptive control system approach is necessary. The implementation of a digital self-tuning control regime for PaO2 is described here. The controller is based on an explicit Linear Quadratic Gaussian (LQG) self-tuning control design which is presented using a polynomial equation approach. The controller performance was investigated in in vitro experiments. The self-tuner performed satisfactorily with various sensor/oxygenator combinations for blood flow and temperature load disturbances. In contrast, a nonadaptive (proportional-integral, PI) type of control system was found to be unsuitable.


An optical three-dimensional technique for topographical descriptions of surgical implants.

The purpose of this study was to develop a noncontacting optical method for the topographical description of surfaces. The method is suitable for all types of surgical implants, including threaded ones. The TopScan 3D system employs a scanning spot and a stationary object at a relatively large working distance to enable proper object alignment, and the depth discrimination property of confocal laser scanning microscopy forms the basis of its surface profiling ability. Scanning is achieved by precision movement of the microscope objective along three orthogonal axes (X, Y, Z). Three-dimensional surface topographical maps are produced by performing a series of parallel XZ scans in Y steps. Eighty seven screw-shaped titanium implants were divided into five groups each with a different surface roughness. The five groups were obtained by varying the size of the blasting particles and by leaving one group 'as-machined'. By using the TopScan 3D approach, we were able to calculate different kinds of surface roughness parameters and to produce visual images from the groups. As expected, the surfaces blasted with large particles showed higher values for the surface parameters than those blasted with smaller particles; the latter had higher values than the 'as-machined' screws.


Image processing system for interpreting motion in American Sign Language.

In this paper, an image processing algorithm is presented for the interpretation of the American Sign Language (ASL), which is one of the sign languages used by the majority of the deaf community. The process involves detection of hand motion, tracking the hand location based on the motion and classification of signs using adaptive clustering of stop positions, simple shape of the trajectory, and matching of the hand shape at the stop position.


Development of a humidifier for patient ventilation using a semi-permeable tube to minimize system condensate.

Condensation in the external airways of patient ventilation systems using conventional warm-water humidifiers increases the risk of bacterial contamination. Condensate formation can be reduced by heating the external airway and reducing the length of tubing between the patient and humidifier. The method described incorporates the humidifying element within the interconnecting tubing itself. Air is supplied through two semi-permeable tubes, of polytetrafluoroethylene, which are encased in an outer shell. A warm-water jacket is maintained in the shell; this is the source of heat and water vapour which diffuses through the semi-permeable tube wall and into the patient's air supply. An evaluation of performance and an initial clinical trial are reported.


Is fetal heart rate monitoring sufficiently sensitive to detect changes during labour?

Although fetal monitoring is a common clinical procedure, there is little quantitative evidence that it can detect changes occurring during labour. We present quantitative data comparing the first and second stage of labour, from 21 labours resulting in a normal fetal outcome. A range of fetal heart rate variables was calculated from the output of a fetal heart rate monitor. Significant changes were detected in baseline fetal heart rate (P less than 0.005), heart rate variability (P less than 0.05), number of dips (P less than 0.01) and their depth (P less than 0.01). The results encourage confidence in the sensitivity of fetal monitoring for the detection of changes in a number of fetal heart rate variables during the course of labour.


Use of hot wire anemometry to measure velocity of the limb during human movement.

Hot film anemometry, x-configuration probes were used in two experiments to evaluate their effectiveness at measurement of limb velocity. Data from tests with a probe attached to the end of a pendulum establish that the hot films measure velocity in the swing phase within 0.098 ms-1. The kinetic energy per unit mass of the pendulum was predicted within +/- 0.005 m2 s-2, from the measured velocity. In gait experiments with one human subject at speeds greater than 0.25 ms-1, the hot film anemometer and a video system predicted speeds within 0.083 ms-1. The hot film data are electronic signals that are easily stored and processed. The results from these experiments demonstrate that hot film anemometry is an effective and efficient method for direct measurement and analysis of the limb velocity.


Influence of metabolic, mechanical and physique variables on middle distance running.

The purpose of this study was to determine the variables that most limit middle distance run performance e.g. 800, 1500 and 3000 meters. A predictive research design was employed as 56 runners ran each of the three distances and were evaluated for VO2max, running mechanics, physique variables, ventilatory threshold, and anaerobic capacity and power. The data were analyzed by correlation procedures and stepwise regression analysis. The variables that most limited 1500 and 3000 meter (m) run performance were identical. Maximal oxygen uptake was the most important, but stride length and anaerobic capacity and power also contributed significantly. Run performance at 800 m was influenced by a considerably different set of variables. Peak velocity was most important, but VO2max, % fat and thigh length also contributed significantly. These data indicate that 1500 and 3000 m runners can compete favorably at either distance, while 800 m runners have a different profile and would experience difficulty competing at 1500 and 3000 meters.


Effect of high velocity resistance training on peak torque, cross sectional area and myofibrillar ATPase activity.

The purpose of this investigation was to determine the effect of high velocity resistance (HVR) training on peak torque (PT), cross sectional area (CSA) and myofibrillar ATPase activity of the knee extensors. HVR training was performed in a circuit on hydraulic exercise equipment, 4 times a week for 5 weeks at an angular velocity of approximately 3.14 rad.s-1. Knee extension PT was determined on a Cybex II isokinetic dynamometer and CSA of the quadriceps femoris muscle was assessed using computer tomography (CT) scanning. Muscle biopsies were obtained from the lateral quadriceps muscle and were analyzed for myofibrillar ATPase activity. Knee extension peak torque was significantly increased at 1.57, 2.09, 3.14, 3.66 and 4.19 rad.s-1. Myofibrillar ATPase activity and CSA was also significantly increased after HVR training. These findings showed that short-term high velocity resistance training enhances the in vivo torque/velocity curve especially at fast angular velocities and these changes are partly attributed to an increase in muscle CSA and activity of myofibrillar ATPase.


Sports-related epiphyseal injuries of the lower extremity. An epidemiologic study.

Sports-related epiphyseal injuries in children and adolescents have been becoming more prevalent during recent years. We report 85 patients with epiphyseal fractures of the lower extremity treated in our hospital during the last twenty years, of which 60 were males and 25 females with an average age of 12.6 years (range 4 to 17 years of age). The injuries were sustained during soccer in 28% and during alpine skiing in 26% of the cases, of which the former was responsible for most of the injuries reported in males and the latter for those in females. The most frequently seen localizations were in the distal tibial epiphysis (31 cases), followed by the distal fibula (17) and the proximal tibial epiphysis (15). Of the reported 85 epiphyseal fractures 30 were Salter-Harris type I injuries, 25 type II, 8 type III and 11 were type IV fractures, while 11 were avulsion fractures. Of these patients, 56% were treated surgically, while conservative treatment was chosen for 44% of the patients. Of the 49 patients available for follow-up, complications were documented in 9 instances, including 3 leg length discrepancies, 4 axis deviations, one avascular necrosis of the femoral head and one case of osteomyelitis, of which 6 required corrective surgery.


Strength training via high frequency electrical stimulation.

Twelve males and twelve females received 18 sessions of high frequency (2500 Hz) electrical stimulation of either the biceps brachii or triceps brachii muscles. Each session consisted of ten 10-second contractions separated by 50 seconds of rest. Pre- and post-test measurements included arm flexion and extension strength, endurance, girths and fatfolds. The analysis of variance revealed that there were no significant differences for any of the pre versus post parameters. These findings suggest that electrical stimulation, by itself, is not an adequate training stimulus in normal healthy muscles. The data support the contention that volitional training is required to gain strength.


Effects of speed training on the fibre composition of the longissimus lumbaris muscle.

Thirty-six adult male and female Wistar rats were divided into three groups, each of which underwent different training programmes in which greater relevance was attached to the intensity of exercise than to its duration. Samples of the longissimus lumbaris muscle taken between the second and fourth lumbar vertebra, were stained with m-ATPase after acid preincubation at pH 4.4, and with NADH-TR. The most notable results obtained were: (a) none of the training programmes involved gave rise to changes in the ratio of type I: type II fibres; (b) the proportion of IIA fibres increased in all cases, while the proportion of IIB fibres decreased correspondingly; (c) the percentage of FT fibres decreased significantly, and in greater proportion than the decrease recorded in IIb fibres, and (d) specific speed training schedules led to greater changes in the fibre composition of this muscle.


Blood lactate, glycerol and catecholamine in arm strokes, leg kicks and whole crawl strokes.

Lactate, glycerol, and catecholamine in the venous blood were determined in 8 recreational swimmers following 60 sec of supramaximal arm strokes, kicks and the whole swim. The mean velocity of a whole stroke was higher than both arm strokes and kicks, and the mean velocity of arm strokes was higher when compared with kicks. There was a significant relationship between the mean velocity of arm strokes and the whole swim (r = 0.90; p less than 0.01). Peak blood lactate in the whole swim was higher than arm strokes (p less than 0.01) and kicks (p less than 0.01), and peak blood lactate in arm strokes was higher compared to kicks (p less than 0.01). The correlation coefficients between mean velocity and peak blood lactate in arm strokes, legs kick and whole swim were r = 0.72 (p less than 0.05); r = 0.61 (n.s.) and r = 0.35 (n.s.), respectively. These results suggest (1) that lactate in the blood during the whole crawl stroke originates predominantly from the muscle groups which work the arm and (2) that glycogen included in the muscles of the upper body which is used during arm strokes was easily convertible into the propelling force during arm swim, while additional energy from the leg muscles is not fully sufficient to increase propulsion force in a linear manner.


Respiratory muscle fatigue does not limit exercise performance during moderate endurance run.

The role of respiratory muscle fatigue in limiting exercise performance in well-trained subjects is still controversial, especially as far as relatively short runs are concerned. To determine the occurrence of respiratory muscle impairment, we studied six well-trained athletes before, during (middle of the run) and after a 17 km run. They were all asked to produce the maximum effort they could during the race. Strength was assessed by measuring maximal inspiratory mouth pressure against close airways (MIP), dynamic lung volumes were monitored using a spirometer. No changes in forced vital capacity (FVC), maximal expiratory flow (PEF) and forced expiratory volume in 1 sec (FEV1) were observed throughout the experiment. This suggested that functional residual capacity and subsequently the initial length of respiratory muscle were unchanged. Respiratory muscle strength did not significantly vary at the different time of measurements (154.8 +/- 20.9 cm H2O at the beginning, 157.5 +/- 23.7 cm H2O after 7.5 km, 155.8 +/- 22.5 cm H2O at the end and 152.3 +/- 17.6 cm H2O after 30 min of recovery). We therefore conclude that respiratory muscle fatigue does not impair the exercise performance of well-trained athletes in a relatively short race. The difference between these results and others reported in literature, could be explained by the different degree of training of the subjects performing the race.


Characteristics of the morphological and functional status of kayakers and canoeists.

A study of anthropometric and functional characteristics was conducted in a sample of 29 athletes, flatwater racers 18 kayakers and 11 canoeists. The results of morphological tests suggest an evident reduction of subcutaneous fat, above-average values of limb circumferences (especially upper limbs) and of body mass, attributable to a high proportion of lean body mass. Trunk extension strength was to be below the average, while the strength of the remaining analyzed static movements were on the level of trained persons. Aerobic capacity, i.e. the functioning of the cardiopulmonary system, in the sample under discussion has shown above-average values, comparable to those obtained in athletes in the aerobic sports group. The results of discriminant analysis applied separately to morphological, dynamogenic and aerobic characteristics with the aim to identify possible differences between the two sports suggest that our sample constituted a homogeneous group, regardless of which of the two sports were practiced.


Diet, hormonal, and metabolic factors affecting bone mineral density in adolescent amenorrheic and eumenorrheic female runners.

Seven adolescent female runners with secondary amenorrhea and six adolescent eumenorrheic female runners received dietary supplements of 1200 mg calcium carbonate and 400 IU vitamin D/d for 12 months. Bone mineral density (BMD) of the axial skeleton was measured by dual photon densitometry at the beginning and end of the 12 month period. Plasma estradiol and ionized calcium concentration were also determined. Bone mineral density decreased in two of the amenorrheic subjects, with the lowest estradiol values concurrent with the severest training regimen and highest calcium intake. There was a significant decrease in plasma estradiol concentration in the amenorrheic runners (p less than 0.05). Plasma ionized calcium and estradiol explained 99% of the variation in BMD (r2 = 0.999). A significant inverse relationship between plasma estradiol and miles run/week was observed (r2 = -0.748). Adolescent female runners who train extensively and have low plasma estradiol levels may be adversely affecting BMD despite supplemental calcium and vitamin D intake.