Transposable element insertions respecify alternative exon splicing in three Drosophila myosin heavy chain mutants

Insertions of transposable elements into the myosin heavy chain (Mhc) locus disrupt the regulation of alternative pre-mRNA splicing for multi-alternative exons in the Mhc2, Mhc3, and Mhc4 mutants in Drosophila. Sequence and expression analyses show that each inserted element introduces a strong polyadenylation signal that defines novel terminal exons, which are then differentially recognized by the alternative splicing apparatus. Mhc2 and Mhc4 have insertion elements located within intron 7c and exon 9a, respectively, and each expresses a single truncated transcript that contains an aberrant terminal exon defined by the poly(A) signal of the inserted element and the 3' acceptor of the upstream common exon. In Mhc3, a poly(A) signal inserted into Mhc intron 7d defines terminal exons using either the upstream 3' acceptor of common exon 6 or the 7d acceptor, leading to the expression of 4.1- and 1.7-kb transcripts, respectively. Acceptor selection is regulated in Mhc3 transcripts, where the 3' acceptor of common Mhc exon 6 is preferentially selected in larvae, whereas the alternative exon 7d acceptor is favored in adults. These results reflect the adult-specific use of exon 7d and suggest that the normal exon 7 alternative splicing mechanism continues to influence the selection of exon 7d in Mhc3 transcripts. Overall, transposable element-induced disruptions in alternative processing demonstrate a role for the nonconsensus 3' acceptors in Mhc exons 7 and 9 alternative splicing regulation.

[Risk factors related to esophageal cancer in Rio Grande do Sul, Brazil]

BACKGROUND

Rio Grande do Sul, a State in southern Brazil, shows high mortality rates for esophageal cancer. Important geographical variations suggest external factors in the etiology.

OBJECTIVE

The relationship between smoking, alcohol and "mate" to esophageal cancer.

METHOD

55 patients with esophageal cancer were interviewed, soon after the endoscopy, about risk factors; 110 patients who did not showed esophageal tumor in the endoscopy were the controls.

RESULTS

Among the patients with esophageal cancer there were more farmer-workers (OD 3.3; 95% CI 0.9-11.2), father with antecedent cancer (OD 6.9; 95% CI 1.9-25.6), smoking and ex-smoking (OD 2.5; 95% CI 1.1-5.9), drinkers and ex- of alcohol (OD 5.3; 95% CI 2.6-11.0), drinkers and ex- of "mate" (OD 3.6; 95% CI 1.3-9.8). Others variables more frequent in the cases were: smoking for > 20 years; kind of alcohol (spirits), drinking alcohol every day, drinking "mate" every day and adding salt to food.

CONCLUSIONS

Smoking, alcohol, "mate", farmer-workers and antecedent of father with cancer were significantly more frequent in the cases of esophageal cancer than in the controls.

[Evaluation of the test strip Reflotron ALP (alkaline phosphatase) for blood samples of dogs and cats]

The test strip Reflotron ALP (alcaline phosphatase) was evaluated for use in canine and feline heparinized blood samples. The within-run and the day-to-day precision of blood and plasma samples was excellent. A haematocrit up to 60% of canine blood and up to 50% of feline blood had no influence on the measurements. Reflotron ALP was compared with ALP on Hitachi 717 (Boehringer Mannheim, Mannheim, Germany). The correlation of both methods was good for canine and feline blood samples. Reflotron ALP was higher than Hitachi ALP in both species. Despite an enormous deviation between Reflotron ALP and the reference method of canine and feline blood samples within the reference range, Reflotron ALP is a suited test for the detection of elevated ALP activity in canine and feline blood samples. Differences of the ALP activity might be caused by ALP isoenzymes. The activity of ALP isoenzymes depends on the method. The buffer systems of Reflotron ALP and Hitachi ALP are different. Significant exceeding of the reference range was reliably detected. In this investigation the study results for heparinized whole blood, heparinized plasma and serum are approximately the same.

Does consumption of beer, alcohol, and bitter substances affect bitterness perception?

The relation between consumption of beer, alcohol, and bitter substances was investigated by comparing 20 each of male adults, low users ( < 720 ml/week) and high users ( > 3.61/week) of beer for sensitivity to and like/dislike for the bitterness of isohumulones. Intake of beer, alcohol, and bitter substances was measured with a food frequency questionnaire and a 14-day recall journal. Intake of alcohol (including alcohol from sources other than beer) and bitter substances was higher for high users of beer than for low users. The average bitterness units (BUs) in the beers consumed by the two groups did not differ, indicating that high users do not consume more bitter beers than low users. Detection thresholds for isohumulones in water did not differ between the two groups, but high users had higher difference thresholds for isohumulones in beer (p < 0.10). In time-intensity measurements of bitterness in beer, low users of beer recorded significantly higher maximum intensities (p < 0.001) and shorter total durations (p < 0.001) than high users, with no difference between the two groups for time to maximum intensity and area under the TI curve. There was no significant difference between the two groups for BUs of beers produced by ad lib mixing of low- and high-bitterness beers, or for mean hedonic ratings of various concentrations of isohumulones in beer. These results suggest that intakes of beer, alcohol, and bitter substances are not major determinants of taste responses to the bitterness of isohumulones.

Clinical decision making by experienced and inexperienced pediatric physical therapists for children with diplegic cerebral palsy

BACKGROUND AND PURPOSE

This qualitative study was designed to explore, identify, and describe clinical decision-making processes used by pediatric physical therapists.

SUBJECTS

Clinical decision-making processes of three experienced therapists and three inexperienced therapists were assessed as they worked with 18 children with diplegia.

METHODS

Retrospective think-aloud procedures were used to elicit verbalizations, which were transcribed, coded, and analyzed.

RESULTS

Four characteristics of clinical decision making were identified: (1) Movement scripts provided insights into the clinical application of cognitive schemata based on previous experiences, (2) procedural changes occurred rapidly during within-session decision making, (3) psychosocial sensitivity was important for positive interaction during therapy, and (4) self-monitoring appeared to be pivotal in making clinical decisions as therapists self-assessed their practice. Contrasting data illustrated similarities and differences of experienced and inexperienced clinicians.

CONCLUSION AND DISCUSSION

Findings are generally consistent with existing clinical decision-making literature and provide important information for physical therapy practice, research, and education.

Susceptibility to high-altitude pulmonary edema in Madison and Hilltop rats. I. Ventilation and fluid balance

The pathogenesis of high-altitude pulmonary edema (HAPE) is not well understood. Ventilation and fluid-handling abnormalities at high altitude (HA) may play a role in HAPE. Because ventilatory and cardiopulmonary responses to chronic HA exposure in the Hilltop (H) strain of Sprague-Dawley rat are different from those in the Madison (M) strain, it was hypothesized that these strains would have different susceptibilities to developing HAPE. M and H rats were studied at sea level (SL) and in a hypobaric chamber after 9 and 12 h at a simulated altitude of 24,000 ft (barometric pressure = 295 mmHg) and 1, 12, and 24 h at a simulated altitude of 18,000 ft (barometric pressure = 380 mmHg). Both strains developed HAPE, but the M rat was more susceptible to HAPE, as demonstrated by a higher mortality rate from hemorrhagic pulmonary edema after 9 h at 24,000 ft and an earlier increase in lung water after exposure to 18,000 ft. Minute ventilation was similar in both strains at HA, but arterial PO2 was significantly higher in the M rat. Both strains had a significant decrease in fluid intake and negative sensible water balance at HA. No changes in plasma renin activity, aldosterone concentrations, antidiuretic hormone levels, and atrial natriuretic peptide levels were found at HA. The increased susceptibility of the M rat to HAPE is therefore not explained by ventilation or fluid-handling abnormalities.

Role of CD11a and CD11b in ischemic acute renal failure in rats

Leukocytes, particularly neutrophils, have been implicated in ischemic-reperfusion organ injury (IRI). However, their role in kidney IRI is controversial. Leukocytes express the adhesion molecules CD11/CD18 on their surface, which mediate many functions that can lead to tissue damage. To determine the role of CD11a and CD11b in IRI in the kidney, uninephrectomized Sprague-Dawley rats were pretreated with monoclonal antibodies (MAbs) directed against CD11a and CD11b or control MAbs. The serum creatinine (SCr), complete blood count, and kidney histopathological damage scores (PDS) (scale: 0-4) were assessed prior to and 24 h after 60 min of ischemia. Mean SCr 24 h after ischemia was significantly decreased in the anti-CD11a- and -CD11b-treated group compared with the control MAb-treated group (2.5 +/- 0.3 mg/dl vs. 3.4 +/- 0.2 mg/dl, P < 0.05). PDS were also reduced in the CD11a and CD11b group compared with controls (2.7 +/- 0.2 vs. 3.5 +/- 0.1, P < 0.001). These data show that the CD11/CD18 leukocyte adhesion pathway plays a role in mediating ischemic acute renal failure in rats.

[Geographical differences in esophageal neoplasm mortality in Rio Grande do Sul]

Mortality data from cancer of esophagus were studied in the 24 microregions of the State of Rio Grande do Sul (RS), Brazil, from 1970 to 1989, in males and females. The mortality data were calculated through information from the Health Department of RS and the population was obtained in IBGE and FEE. The average, the standard deviation and, by linear regression, the angular parameter of the temporal series for the State and each microregion, were calculated. We noticed great differences between the average of death rates in the 24 microregions, with values between 16.49 to 4.74, in males. The microregions of the south of the State, where there are many farms, revealed higher death rates of mortality by esophageal cancer. The tendency showed to be ascending in 54% of the microregions, in the males.

Salt loading test in a population adapted to moderately high altitude living (3,000 m)

The sodium excretory capacity of normal subjects acutely mobilized from sea level to moderately high altitude was compared to native subjects adapted to high altitude living (3,000 meters). This study was conducted in order to provide insights into hormonal adaptations associated with acute mobilization to a hypoxemic environment and to try to determine how these variables could influence the renal handling of a salt load. A standard amount of 5% NaCl solution at a volume of 100 ml/m2 BSA was infused over a 30-min period to all subjects. Urine collections were obtained periodically over the next 3 h. Subjects adapted to moderately high altitude living were able to excrete a salt load faster than unadapted subjects (57.1 vs. 32.9 mmol.m-2.h-1, respectively). No change in plasma atrial natriuretic factor (ANF) concentration in either group of subjects was observed during the salt administration period. Adapted individuals had significantly higher baseline levels of antidiuretic hormone (ADH). The high altitude natives enhanced excretory response to a salt load was not explained by any observed hormonal changes and their lack of increased ADH release to serum osmolar changes was unexplained.

[Mortality from uterine cervix cancer in Rio Grande do Sul]

The mortality from cervical cancer was studied by checking the death rates in Rio Grande do Sul (RS) and in its 24 microregions. Each tendency (linear regression), in the period from 1970 to 1989, was also investigated. We have also studied the relative rates of this kind of cancer, the comparison with the rate in other places and the risk factors. The data were obtained at the Office of Health in Rio Grande do Sul as well as in the Statistics and Geography Brazilian Institute and World Health Organization. The average mortality rates/100,000 women in RS (1970-1989) was 3.8, with ascending tendency. Important differences in the death rates in the 24 microregions in RS were observed and they ranged from 2.5 to 6.7. The cervical cancer was the fourth cause of death in women from RS (mortality by cancer), in 1989. Papillomaviruses and smoking were important factors in the development of cervical cancer.

Hormonal response to exercise in high altitude natives and COPD patients

Plasma renin activity (PRA) and aldosterone increase with exercise. Acute hypoxia interferes with this hormonal response to exercise, but the effects of chronic or intermittent hypoxia on exercise-induced hormonal changes are not well understood. The hormonal response to exercise was studied in two groups of subjects who were expected to become hypoxic during exercise (high altitude natives at high altitude and patients with moderate to severe chronic obstructive pulmonary disease or COPD), and normal controls. Both the high altitude natives and COPD patients became hypoxic with maximal exercise. The rate of rise of PRA and epinephrine was significantly less in the two study groups than the normal subjects. Changes in aldosterone levels with exercise were similar to PRA but the differences among groups were not significant. Differences between the groups were not seen for changes in atrial natriuretic polypeptide and norepinephrine during exercise. These results support the concept that hypoxia interferes with the renin-aldosterone and adrenal medullary response to exercise.

Growth hormone alters lipolysis and hormone-sensitive lipase activity in 3T3-F442A adipocytes

While growth hormone (GH) has long been known as a lipolytic hormone, it has been difficult to study the cellular mechanisms for this effect. Since cultured 3T3-F442A adipocytes have recently proven to be useful to study chronic effects of GH on adipocyte metabolism, we examined the effects of GH on lipolysis. In these cells, GH alone produced a dose-dependent increase in the release of glycerol after 24 to 48 hours. The maximum increase occurred with 10 ng/mL human GH. The effect of GH was similar in the presence and absence of dexamethasone. Under each condition, the stimulation of glycerol release was accompanied by a GH-induced increase in the activity of hormone-sensitive lipase (HSL), a key lipolytic enzyme. The increase in HSL required 24 hours with GH and lasted at least 48 hours. The increase in HSL activity by epinephrine, like glycerol release, was potentiated by GH. Although GH potently simulates the activity of the lipogenic enzyme glycerol phosphate dehydrogenase (GPD) in differentiating 3T3-F442A preadipocytes, GH had a negligible effect on GPD activity in the differentiated adipocytes with chronic or short-term incubation. However, in contrast to the chronic effect of GH, short-term (30-minute) incubation with GH inhibited epinephrine-stimulated glycerol release, a characteristic transient antilipolytic effect of GH. These studies indicate that chronic GH treatment is lipolytic in cultured 3T3-F442A adipocytes, and document that lipolytic responses to GH involve an increase in the activity of HSL.

Differential regulation of two glucose transporters by chronic growth hormone treatment of cultured 3T3-F442A adipose cells

New methods for the analysis of glucose transporters were used to analyze the molecular mechanisms involved in the insulin-antagonistic effects of growth hormone (GH), which is known as a diabetogenic hormone. The ability of GH to alter the number and mRNA levels of two different glucose transporters in cultured 3T3-F442A adipocytes was investigated using specific antibodies and cDNA probes. At concentrations of GH as low as 0.5 and 5 ng/ml and at incubation times as short as 4 h, GH decreased rates of 2-deoxyglucose uptake in 3T3-F442A adipocytes. 3-O-Methyl-D-glucose uptake was inhibited to an extent similar to that of 2-deoxyglucose uptake (60-80%) after a 24-h incubation with GH (500 ng/ml), indicating that GH inhibits glucose metabolism specifically at the step of glucose transport. To determine whether reduced rates of glucose transport might result from reduced numbers of glucose transporters, whole cell lysates were prepared from GH-treated cells and subjected to immunoblotting using antibodies that identify Glut 1 (HepG2/rat brain) and Glut 4 (muscle/adipose) transporters. GH caused a time- and dose-dependent decrease in the number of Glut 1 transporters in the cell. Northern and slot-blot analyses showed a GH-induced dose-dependent decrease in levels of Glut 1 mRNA. In contrast, levels of Glut 4 transporter and mRNA were unchanged by GH. These data suggest that GH regulates Glut 1 and Glut 4 transporters differentially and that it exerts its inhibitory effect on glucose uptake at least in part by decreasing the synthesis of Glut 1 transporters. These studies provide the first evidence that GH regulates a key gene in metabolic regulation and can interfere with gene expression.

Forces in the halo-vest apparatus

A previous study by Koch and Nickel (1978) determined the changes in the distraction forces in the halo-vest during different activities. The present study determined the variations of forces in different directions between the halo and the vest also during different activities. Clip-on strain gauges were used to measure the strains in the bars, while an on-line computer system was used to compute the forces. Anterior-posterior forces were found to be comparable with vertical ones. These forces and the changes during a particular activity were caused by gravity forces of the head in activities involving a change in attitude; and vest distortion from changes in body shape, direct pushing from the lower abdomen, the arms and shoulders, or from supporting surfaces. Activities producing the highest force changes included bending forwards from a seated position and reaching over sideways while lying. Medial-lateral forces were small in comparison with vertical and anterior-posterior forces. Implications of the study were that pin-skull forces were multidirectional, and that certain improvements in design could be effected by accounting for the factors causing high forces and consequently cervical motion.

[Chondrolysis with protrusion and stiffness of the hip in puberty]

With reference to 5 recently observed cases, and after a review of the literature, the rare and hitherto inadequately clarified complex of stiffness of the hip in puberty is considered. The primary condition--chondrolysis, not necrosis of the head--is typified by destruction with subsequent layered fibrosis of the tissue at the cartilage/bone transition point, mainly at the head of the femur and the acetabulum. The clinical picture is an independent one, accompanied by synovitis and in severe cases leading to fibrous ankylosis. It is not only seen in females with deep and protruding acetabuli, beginning usually between the ages of 10 and 16; it also occurs as a complication of femoral head epiphysiolysis in boys and occasionally also after trauma and inflammations in the hip region. In severe cases the treatment of these events, which even occur occasionally on the "healthy" side, is unsatisfactory. Early relaxation surgery still seems to be the most effective treatment, by reducing the pressure on the base of the acetabulum which probably occurs in these cases. All treatment should be performed in carefully timed and measured stages, "sneaking up" on the irritation.

Energy-dependent extrusion of cyclic 3',5'-adenosine-monophosphate. A drug-sensitive regulatory mechanism for the intracellular nucleotide concentration in rat erythrocytes

In reticulocyte-rich suspensions of red blood cells from rats extrusion of cAMP as a regulatory mechanism of intracellular cAMP was investigated. In response to isoprenaline and/or the phosphodiesterase inhibitors Ro 20-1724 and rolipram extrusion of cAMP increases dependent on the concentration of the drugs and time of exposure. However, these drugs exert their effects on the extrusion of cAMP only indirectly, i.e. via increased intracellular levels of cAMP, since the respective EC50-values of the drugs for intracellular accumulation and extrusion of cAMP are identical (isoprenaline: approximately 50 nM; rolipram: approximately 1 microM; Ro 20-1724: 15 microM). The dependence of the rate of extrusion on intracellular levels of cAMP is characterized by a typical concentration-effect relationship from which a maximal capacity of cAMP extrusion of 3-6 nmol/10 min/10(9) cells and a half maximal effective intracellular cAMP concentration of 40-50 nmol/10(9) cells can be derived. This relationship has been inferred from either kinetic or steady-state approaches. At rapidly changing intracellular levels of cAMP an apparent time lag of extracellular cAMP accumulation is obligatorily conditioned by this relationship. Vasodilating drugs which lower the ATP content of the cells as well as the uncoupler of oxidative phosphorylation, FCCP, inhibit the extrusive process (papaverine greater than FCCP greater than dipyridamole greater than dilazep much greater than hexobendine greater than or equal to carbocromene) leading to a 3-5-fold increase of the intrato extracellular concentration gradient of cAMP. It is concluded that extrusion of cAMP is a saturable and energy-dependent process which regulates the intracellular cAMP concentration independent of the activities of adenylate cyclase and phosphodiesterase.

[Prognosis of leg length difference in congenital fibula defect]

Predetermination of leg length discrepancy, which has to be expected in patients with congenital defects of the fibula, is very useful for the treatment program. Taking morphologic aspects and the principles of growth into consideration it is possible to predict quite accurately the final leg length in unilateral fibula defect. The prognosis is based on the finding, that the percentage longitudinal deficiency is constant during the growth of the lower limb. The calculation of the absolute leg length is done by assistance of the diagrams by Anderson and coworkers. The overall length discrepancy of unilateral hypoplasia of the fibula exceeds 8.5 cm. In cases of fibula aplasia a discrepancy of more than 10 cm. has to be expected. We saw this severe deformity on more than 50% of our cases. Experience supports the conclusion that preservation of the foot even by a number of reconstructive operations gives mostly better results than early amputation and provision of a prosthesis. There is a good chance to achieve limb-length equality by operations in cases of fibula hypoplasia type IA and IB. This chance is limited in hypoplasia type II and absence of the fibula.

Myoclonus and ocular oscillations induced by L-tryptophan

A patient with chronic manic-depressive illness developed generalized myoclonus and spontaneous ocular oscillations after a single 2 gm dose of L-tryptophan. She had been pretreated with both a tricyclic antidepressant and a monoamine oxidase inhibitor. The involuntary movements gradually disappeared within 24 hours after the drugs were discontinued. Electrooculographic recording 7 hours after onset of the abnormal eye movements revealed square-wave jerks and hypometric voluntary saccades. Pursuit as well as optokinetic and vestibular slow phases were normal except for superimposition of the square-wave jerks. Repeat recording 24 hours later was entirely normal.

Cystinuria in the maned wolf of South America

Of 42 maned wolves in zoos or live-trapped in Brazil, 34 had excessive cystine in their urine. Renal clearance studies of five of the affected wolves revealed a variable defect for the reabsorption of cystine and dibasic amino acids. The renal tubular handling of other solutes including glucose, phosphate, sodium, potassium, and uric acid was considered normal. Urinary calculi composed of cystine were found in four wolves and proved fatal in three of them. With the exception of the high incidence in this species, this hereditary disease resembles the disorder described in dogs and humans.