Sex difference in mortality rates of Leghorn-Red reciprocal crosses

Mortality rates among White Leghorn-Rhode Island Red pure-line and reciprocal cross adult female progeny were recorded for 8 years. The mortality rate among progeny of White Leghorn males exceeded that of the progeny of Rhode Island Red males in both pure-line and crossbreds. White Leghorn X Rhode Island Red crossbred progeny had the highest mortality rate. In a second phase of the study, a comparison was made between mortality rates of male and female progeny of White Leghorn-Rhode Island Red reciprocal crosses. Rate of loss was significantly lower in males than in females but did not differ between crosses. These results support a conclusion that sex linkage is a major factor in differential mortality rates between progeny of White Longhorn-heavy breed reciprocal crosses.     

Chondrosarcoma of the jaw and facial bones

BACKGROUND: Osteosarcomas of the jaw frequently have chondroblastic differentiation, causing confusion with chondrosarcomas. METHOD: Clinicopathologic features and results of treatment were analyzed for a series of 56 patients (27 males and 29 females from 1.5 to 88 years of age) with chondrosarcoma of jaw and facial bones. Twelve patients (21.4%) were younger than 20 years. RESULTS: The major symptom was nasal obstruction or a painless mass; the median interval from the first symptom until initial treatment was 1 year. Of the 56 chondrosarcomas, 25(44.6%) involved the alveolar portion of the maxilla and maxillary sinus; 23 (41.1%) involved the nasal septum, ethmoid, and sphenoid; 6 (10.7%) involved the mandible; and 2 (3.6%) involved the nasal tip. Of the 19 patients with radiographic studies, 15 (78.9%) had an expanding soft tissue mass with varied matrix calcification and destruction of bone and 2 had a purely lytic lesion. The lesion was difficult to assess in the two others. Most tumors had a lobulated growth pattern of hyaline cartilage. Hypercellularity, nuclear pleomorphism, and binucleation were common features. Forty-three tumors were grade 1, 13 were grade 2, and none were grade 3. Modalities of treatment were known for 51 of the 56 patients. Forty-six patients (90.2%) had surgical treatment, 2 (3.9%) had combination radiation therapy and chemotherapy, 1 (2%) had radiation therapy alone, and 2 (3.9%) had biopsy only. Follow-up adequate for analysis was obtained for 42 patients. Of these, 14 (33.3%) had local recurrence; uncontrolled recurrence developed in 9 (21.4%) patients. No distant metastases were documented. Overall actuarial survival at 5, 10, and 15 years was 80.7%, 65.3%, and 56%, respectively. Survival was analyzed for location, size, and histologic grade of tumor. No statistically significant differences were found. CONCLUSIONS: Chondrosarcomas of the jaw and facial bones are extremely rare, locally aggressive tumors.     

THE SIMULATION OF DISPERSED-PHASE BREAKAGE PHENOMENA

Droplet breakage in emulsification occurs as the result of work performed against surface tension by dynamic pressure fluctuations while deaggregation in biological wastewater treatment occurs in response to hydrodynamic stresses imposed by aeration, recirculation, and mixing. Such size reduction in the latter case leads to solids carry-over and poor process performance due to reduced sludge age. Laboratory observations of the disintegration process have shown how the hydrodynamic environment causes breakup and lean, batch breakage studies have indicated the most probable sizes of fragments. A Monte-Carlo type simulation has been used successfully to model the breakage process in both liquid-liquid and solid-liquid systems under high dissipation conditions.     

The pathomechanics of compression injuries in the cervical spine. Nondestructive and destructive investigative methods

Biomechanical analysis using nondestructive and destructive investigative methods was performed to evaluate the mechanisms of cervical compression injuries. These injuries produce two basic modes of failure: 1) anterior dislocation; and 2) rupture of the anterior ligamentous complex of the vertebral body. Distribution of these two failure patterns was determined by the initial cervical spine position; translational alignment did not have a significant effect. Different results were observed between spines positioned in flexion and extension, indicating that the most important factor determining the mode of failure was rotational alignment in the sagittal plane.     

Gender and haplotype effects upon hematological manifestations of adult sickle cell anemia

We evaluated the rates of short-term neonatal complications, neonatal brain damage or mortality in a group of 96 singleton pregnancies complicated by hypertension and electively delivered before 36 weeks gestation. The neonatal outcome of these pregnancies was compared with that of a matched control group of 192 uneventful pregnancies delivered because of spontaneous preterm labor or premature rupture of membranes. Although the rates of acidosis, apneoic crises, bradycardia and ventilatory support were higher among cases than controls, the risk of intraventricular hemorrhage, severe brain damage (grade III-IV intraventricular hemorrhage or periventricular leucomalacia) or neonatal mortality were comparable between the two groups. Neonatal complications were more frequent among infants born to mothers with severe hypertension or severe proteinuria. In conclusion, this study has shown that short term neonatal complications after elective preterm delivery in hypertensive pregnancies are increased in comparison with low risk controls. However, these complications, which were well managed in our intensive care nursery, did not affected neonatal mortality or severe brain damage.     

Low Frequency Oscillations in Longitudinal Power Systems: Experience with Dynamic Stability of Taiwan Power System

Sustained low frequency oscillations have been observed in Taiwan power system which is of longitudinal structure. It is the purpose of this paper to examine the various factors affecting the damping characteristics of these oscillations which caused dynamic instability problem in the operation of Taiwan power system. It is observed that the amount of power flow on the EHV transmission line and the characteristics of load have a significant effect on the damping of the system while the speed-governing system and the gain of automatic voltage regulator have only a minor one. Detailed investigation using both the frequency domain and time domain approaches also reveals that power system stabilizers can be employed as an effective means for improving dynamic stability of Taiwan power system.     

Antibiotic susceptibility of Mycoplasma fermentans strains from various sources and the development of resistance to aminoglycosides in vitro

Mycoplasma fermentans strains reputedly from human infections or tissue culture cells were much more susceptible to azithromycin than to clarithromycin or erythromycin. Lincomycin, clindamycin and several tetracyclines also exhibited good mycoplasmastatic activity but mycoplasmacidal concentrations were substantially greater than the MICs. Ciprofloxacin was the most active of three fluoroquinolones tested and was mycoplasmacidal at concentrations close to the MIC. Tiamulin and mupirocin were also very active. Synergy with specific M. fermentans antiserum plus guinea-pig complement was not observed with any class of antibiotic although the number of viable mycoplasmas was markedly reduced by the combined immunological components. Marked differences in susceptibility to various aminoglycosides were observed. Human strains isolated in cell-free media up to 1967 were aminoglycoside susceptible (MIC range 0.5-25 mg/L) but recent human isolates and strains isolated from tissue culture cells often showed either single or multiple aminoglycoside resistance (MIC > 500 mg/L). Two aminoglycoside-susceptible strains developed resistance to streptomycin or neomycin (> 500 mg/L) within five passages in broth containing streptomycin or neomycin, respectively. Resistance to tobramycin, kanamycin or gentamicin emerged after seven, eight and 14 cycles of exposure to the respective antibiotic. Streptomycin resistance was associated with a five-fold increase in resistance to tobramycin. Neomycin-, kanamycin-, gentamicin- and tobramycin-resistant variants showed mutual cross-resistance but remained susceptible to streptomycin. Induced resistance persisted for at least 17 passages in aminoglycoside-free broth. The use of aminoglycosides in human medicine and the frequent inclusion of some of these drugs in tissue cell cultures to combat bacterial and mycoplasmal contamination might account for the aminoglycoside resistance of recent M. fermentans isolates.     

Cooperative study on the radioimmunological thyrotropin determination (hTSH) in serum (author''s transl)

The increased incidence of drowsiness in hypoalbuminemic patients administered diazepam and more rapid clearance of tolbutamide in cirrhotics may be due to changes in plasma protein binding. The binding of diazepam and tolbutamide was studied by equilibrium dialysis at 37degreesC over a total drug concentration range of 1 to 10 mug/ml and 50 to 300 mug/ml, respectively, in plasma from 21 normal and 14 alcoholic subjects. At 1 mug/ml, diazepam plasma protein binding (+/- S.D.) was 98.5+/-0.4 per cent in normals and 97.8+/-1.2 per cent in alcoholics; at 100 mug/ml, tolbutamide binding was 97.8+/-0.3 per cent in normals and 95.1+/-4.2 per cent in alcoholics. For both agents at all concentrations, the binding to plasma from alcoholics was significantly decreased (P less than 0.01-less than 0.02). The extent of binding of both drugs was dependent on the albumin concentration. These findings suggest that important changes in pharmacologic effect, distribution, and clearance of diazepam and tolbutamide can be anticipated in alcoholics with hypoalbuminemia.