Computed tomography, ultrasound and lymphography in the diagnosis of malignant lymphoma

Lymphographic findings were compared with the results at histopathology in 42 laparotomized patients with malignant lymphoma. Of 12 patients with lymphographically suggested lesions in normal-sized lymph nodes, only one had pathologic changes at histologic examination. Computed tomography gave a better idea of the extent of the disease than lymphography. Moreover, CT had an equal diagnostic accuracy as lymphography for demonstrating enlarged para-aortic lymph nodes. CT should therefore be able to replace lymphography in examination of malignant lymphoma. Ultrasound had the same diagnostic accuracy as CT regarding the upper and middle abdomen but not in the lower abdomen. Ultrasound is of special value in thin patients and when guided needle biopsy is required.     

Vasodepressor effects obtained by drugs acting on the ventral surface of the brain stem

1. In cats anaesthetized with I.P. pentobarbitone sodium and atropinized with intravenous atropine methyl nitrate, the effects on arterial blood pressure were examined of nicotine, physostigmine, carbachol, glycine and pentobarbitone sodium applied to the exposed ventral surface of the brain stem by means of paired Perspex rings placed across the medulla. The drugs were placed inside each ring in a volume of 10mul. 2. Nicotine (0-5-6mg/ml.) produced a fall in blood pressure when the upper limit of the areas covered by the rings was about 5-6 mm caudal, but not when it was just caudal to the trapezoid bodies. The depressor effect was obtained both on bilateral and unilateral application. After application the nicotine sensitive area became for several minutes insensitive to its renewed application. 3. The depressor effect of nicotine was sensitive to hexamethonium (50 mg/ml.) but resistant to atropine (50 mg/ml.) similarly applied. 4. When the nicotine sensitive areas had become insensitive to nicotine, bilateral carotid occulusion produced its normal sustained pressor response. 5. By applying the nicotine through a single Perspex ring which could be moved stepwise along and across the medulla, the nicotine sensitive area was localized and the highest sensitivity was found in a region around and a little caudal to the rootlets of the XIIth cranial nerve. 6. Physostigmine (25 and 50 mg/ml.) and carbachol (6 mg/ml.) produced a fall in blood pressure when the uppermost limits of the areas covered by the paired rings were 5-6 mm caudal to and also when they were just caudal to the trapezoid bodies. From both regions the effects were obtained on bilateral and unilateral application. Their depressor effects were sensitive to atropine but resistant to hexamethonium similarly applied. 7. Glycine (200 mg/ml.) and pentobarbitone sodium (100 mg/ml.) produced scarcely any blood pressure effects when applied bilaterally to the nicotine sensitive areas but produced strong depressor effects on more rostral application, i.e. when the uppermost limit of the areas covered by the rings were just caudal to the trapezoid bodies. 8. It is concluded that the ventral surface of the medulla contains at least two bilateral areas from which vasodepressor effects are obtained on topical application of drugs: a more caudally situated one which is sensitive to nicotine, but insensitive to glycine and pentobarbitone sodium; a more rostrally situated one which is insensitive to nicotine but sensitive to glycine and pentobarbitone sodium; and both areas are sensitive to carbachol and physostigmine.     

Invisible colleges as science elites

An intensive investigation of the American science advisory system failed to find indications of elite structure in the selection or patterns of service of advisors. Advisory groups cannot act as elements of the invisible college circuits thatPrice refered to. The only long term advisors areex officio members.Advisory committee growth and activity is marked by three periods: 1951 to 1957, slow growth; 1957 to 1966, rapid growth; and 1967 to 1972, no growth. Combined with the pattern of growth in numbers of eligible scientists, a perception of elite control may have been created.     

How the Cyber Defense Exercise Shaped an Information-Assurance Curriculum

In this article, we provide a brief history of the Cyber Defense Exercise (CDX), describe Air Force Institute of Technology (AFIT's) participation in it, and explain how the experience shaped the information-assurance curriculum and course format at AFIT. The CDX is an annual competition designed to give students the opportunity to learn and demonstrate best practices in defensive information assurance. The CDX's fundamental objective is to design and implement a network that provides specified IT services and defend it against an onslaught of cyberattacks and natural events. CDX participants included blue forces (students), red forces (attacker) and a white cell.     

Triiodothyronine and thyroxine interrelationships in health and disease

With the recent development of radioimmunoassay techniques for the measurement of serum triiodothyronine (T3) concentration, new concepts have arisen regarding the biologic role of T3 in health and disease and its interrelationships with thyroxine (T4). An awareness of the influence of clinical conditions that affect binding of thyroid hormone to plasma proteins is required in the interpretation of moderately increased or decreased serum T3 values. Hormone preparations containing T3 may produce transient increases in T3 concentration into the hyperthyroid range. Measurements of serum T3 concentration appear to be particularly indicated in clinical situations in which hyperthyroidism is suspected but serum T3 resin uptake and serum T4 values are normal, to exclude the T3-toxicosis syndrome. Also, when serum T4 values are in the hypothyroid range, measurement of serum T3 as well as serum thyrotropin (TSH) concentrations can lead to recognition of abnormalities in thyroid gland biosynthesis. Before a diagnosis of hypothyroidism is made on the basis of a low serum T3 value, one must exclude a variety of clinical nonthyroidal conditions that can result in changes in plasma T3 protein binding or impaired peripheral conversion of T4 to metabolically active T3 without producing a hypometabolic state.     

Critical periods in the development of mutants in scute Drosophila melanogaster

Thermosensitive periods of the development of germs of separate pairs of macrochaetae were studied in two lines of mutation of scute Drosophila melanogaster (y/sc4B and cs7). The experiments have revealed the following three features which had not been observed earlier in similar investigations in other mutants of drosophila: 1) change of thermosensitivity in mutants sc7 in different periods of ontogenesis; 2) different sensitivity in mutants of both lines in different critical periods of the same pair of macrochaetae; 3) discrete sensitivity of separate macrochaetae in mutants of both lines at different stages of oogenesis when there are no germs of these organs yet. The change of penetrability of the mutation of scute for scuttellar macrochaetae in mutants y/sc4B caused by the 90-minute-long heating of larvae on the 4th day of their life (critical period of development) is inherited in 15 observed generations of the maternal line. One may consider these periods of the increased thermosensitivity to be tje periods of stepwise determination of germs of separate pairs of macrochaetae.