Molecular size of IgG in patients with focal glomerulosclerosis

Nineteen patients with focal glomerulosclerosis and with anomalously high clearance of IgG into the urine have been investigated by G.200 column chromatography. The findings are compared with normal sera, with 14 patients with minimal change disease and with 12 patients with proliferative glomerulonephritis. No significant reduction in the molecular size of IgG was found as compared with normal sera and the other diseases in 18 of the patients. In patients with minimal change disease and focal glomerulosclerosis an increased proportion of the IgG eluted in the void volume     

Visceral fungal infections due to Petriellidium boydii (allescheria boydii). In vitro drug sensitivity studies

Four patients with visceral infections due to the fungus Petriellidium boydii, who were recently hospitalized in our institutions, are described. Three of the patients were compromised hosts; in the fourth patient, infection occurred after trauma. All had received prior steroid and antibiotic therapy. Studies of patients with mycetoma or secondary infection of a pulmonary cavity due to this organism and of patients with visceral infections are reviewed. Because of histologic similarities to Aspergillus species, infections due to P. boydii may have been misdiagnosed in the past if the infecting fungus was not isolated in culture. The fungus has been shown to be resistant in vitro to currently available antifungal agents. Resistance to amphotericin and 5-fluorocytosine is demonstrated in our studies. There are few reports of successful chemotherapy of any manifestation of this infection, and no such reports of visceral disease. We demonstrate in vitro sensitivity of isolates in our cases and in others to micronazole, a new antimicrobial agent; this drug may be indicated for treatment of disease due to P. boydii.     

Functional characterization of primary vestibular afferents in the frog

1. In order to more accurately identify the nature of the vestibular input to central neurons, the response properties of single semicircular canal and otolith units in the frog VIIth nerve were studied in curarized preparations. 2. An equation describing the response plane was calculated for each canal on the basis of null point measurements. These results show that the ipsilateral canal planes are orthogonal within 2-5 degrees, and the pairs of right-left synergists are essentially coplanar. A head position of 10-20 degrees maxilla nose up produces optimal horizontal canal and minimal vertical canal activation with horizontal rotation. 3. The frequency response of the horizontal canal was examined in the range 0.025-0.5 Hz. Comparatively shorter phase-lags and a 10 fold greater acceleration gain in this frequency range distinguish the frog from the mammalian species studied. 4. Otolithic responses were tonic, phasic-tonic, and phasic in nature. The preponderance of the latter two groups is stressed (94%). Tonic responses were proportional to the gravitational vector change. Phasic responses were proportional to velocity during transitions in head position and phase-led displacement (30-80%) with sinusoidal acceleration in roll and pitch. 5. Efferent vestibular neurons respond to rotation in the horizontal (usually Type III) as well as vertical planes. Responses in the vertical planes result from canal and/or otolithic input to these neurons indicating that the vestibular efferent system receives extensive multi-labyrinthine convergence.     

Effects of beta-hydroxybutyrate, glycerol, and free fatty acid infusions on glucagon and epinephrine secretion in dogs during acute hypoglycemia

The importance of glucagon in the regulation of carbohydrate metabolism is clearly established. However, the role played by this hormone in the regulation of the overall fuel economy is less certain, particularly with respect to such nonglucose fuels as free fatty acids, glycerol, and ketoacids. In order to elucidate glucagon's role with respect to the latter substrates, dogs were infused with solutions of these three fuels, and their A-cell responses to concomitant insulin-induced hypoglycemia were studied. In addition, epinephrine levels were also monitored. It was found that while these infusions failed to suppress glucagon release, the ketoacid infusion did significantly reduce epinephrine secretion during the insulin-induced hypoglycemic period. It was therefore concluded that glucagon secretion under these experimental conditions is not responsive to prevailing non-glucose fuel levels. Indeed, these data suggest that the sympathetic nervous system may play an important role in the regulation of the over-all fuel economy.     

Sex-differences in the agonistic behavior of spiny-mice (Acomys cahirinus)

Observations of 8 groups each containing three adult spiny mice (Acomys cahirinus) revealed that instances of chasing and physical displacement were quite common, while fighting and biting were rarely observed. The relationships between the most frequent behavioral categories were presented in a correlation matrix. In a second study, females tested in their home cages were dominant over males. In the males' home cages, however, no differences in the frequency of female vs. male aggression were observed. More instances of aggression were observed in the cages of the females than in the cages of the males.     

Histologic structures preserved for 21,300 years

Histologic examination of rehydrated tissue samples from late Pleistocene (Alaskan) mammal mummies demonstrates that the preservative effect of freezing and drying extends to remains 15,000 to 25,000 years old. Some muscle and liver tissue retained identifiable histologic structures. Most tissues were completely disintegrated and partly replaced by masses of bacteria, an indication of considerable postmortem decay before the remains were entombed beneath the permafrost zone.     

Structure and function of immunoglobulin domains. V. Binding, University of immunoglobulin G and fragments to placental membrane preparations

Fc receptors have been shown to be present in human placental tissue with properties distinct from those on macrophages and lymphocytes. A single class of receptor was observed with an intrinsic affinity 4X 10(6) M-(1) for human IgG1. The order of affinity for IgG subclasses was IgG1 = IGG1 greater than IgG3 greater than IgG4. IgA and IgM were not bound. Fc from IgG1 bound with the same affinity as the whole molecule and to the same number of receptor sites, 2 X 10 (12)/mg placental protein. IgG1 was no longer boung after mild reduction and alkylation whereas the binding of Fc was unaffected by this treatment. Neithe C3 nor C3, the two domains which comprise the Fc region of IgG1, bound to the placental receptor. This implies that this Fc receptor is unlike those found on most cell surfaces and that plasental binding is an exception to the theory that each domain has evoked to perform independent functions.     

Obstetrics: basic equipment needs

Nocturnal peaks in core body temperature of rats during the estrous cycle were highest during the night of ovulation (2300-0200 h, proestrus-estrus) and lowest during the night before (diestrus 2-proestrus). Less dramatic diurnal secondary peaks, absent only during estrus, occurred 3-4 h after the onset of daylight. After induction of pseudopregnancy, mean temperature declined, but both daily peaks persisted until the first postluteal estrus, when the secondary peak was again absent transiently. Ovariectomy reduced mean core temperature and abolished all secondary peaks. In contrast, castration during pseudopregnancy did not abolish the secondary peaks. When cyclic rats were gonadectomized (abolishing the secondary rhythm) it was possible to re-establish this rhythm by stimulating the uterine cervix (as if to induce pseudopregnancy). However, in animals exposed to darkness (which also abolishes the secondary rhythm) reinduction by cervical stimulation was ineffective. These results indicated that the integrity of the secondary peak, though dependent on photoperiod, nevertheless was influenced by a neuroendocrine reflex arc.