Immunocytochemical localization of glucocorticoid receptors in cells, cytoplasts, and nucleoplasts

A monoclonal antibody has been used to assess the intracellular localization of the glucocorticoid receptor in rodent L-929 fibroblasts and GH3 pituitary tumor cells. Whole cells from both cell lines showed immunoreactivity in the cytoplasm and nucleus. However, when cytoplasts and nucleoplasts of these cells were examined, only L-cells showed strong antibody binding in both fractions; in contrast, GH3 cells exhibited nuclear staining and slight cytoplasmic staining. These results are discussed in terms of the current findings regarding the intracellular location of steroid hormone receptors.     

New fossil anthropoids from the middle Miocene of East Africa and their bearing on the origin of the oreopithecidae

Recent paleontological collections at the middle Miocene locality of Maboko Island in Kenya, dated at 15-16 million years, have yielded numerous new specimens belonging to at least five species of fossil anthropoids. The most common species of ape at the site, a medium-sized primate with a very distinctive dental morphology, clearly represents a previously undescribed taxon. When compared with other Miocene anthropoids from East Africa, it has its closest affinities with the poorly known species Rangwapithecus vancouveringi from the early Miocene locality of Rusinga Island. The species from Maboko Island is described here as belonging to a new genus of fossil anthropoid, to which "Rangwapithecus" vancouveringi is also referred. The new genus has a highly distinctive suite of derived characters of its molars and premolars, which it shares with Oreopithecus bambolii from the late Miocene of Europe. These synapomorphies indicate a close phyletic relationship between the East African species and Oreopithecus and form the basis for the inclusion of these taxa in a single family, the Oreopithecidae Schwalbe, 1915. In many respects, however, the East African forms are more conservative than Oreopithecus, and in a general sense they can be regarded as an intermediate grade between Oreopithecus and the more generalized early Miocene catarrhines, the proconsuloids. There is, therefore, good fossil evidence to indicate that the origins of the Oreopithecidae can be traced back to the early Miocene of Africa.     

The human placenta contains two distinct binding and immunoreactive species of insulin-like growth factor-I receptors

Two species of insulin-like growth factor-I (IGF-I) receptors in human placenta have been delineated on the basis of their immunoreactivity with an autoantiserum (B-2) to the insulin receptor. When all the IGF-I binding sites in solubilized human placenta were assayed by polyethylene glycol precipitation, a curvilinear Scatchard plot was obtained which could be resolved into two single classes of binding sites: one immunoprecipitable by B-2 IgG and the other, nonimmunoprecipitable. The B-2 reactive sites bound IGF-I with lower affinity (Kd = 7.1 X 10(-10) M) than the B-2 nonreactive sites (Kd = 2.1 X 10(-10) M) and cross-reacted more readily with insulin, the IGF-I/insulin-binding potencies being congruent to 120 and congruent to 1100, respectively. Both receptor subtypes bound IGF-I with congruent to 30-fold higher affinity than multiplication-stimulating activity, and, after affinity cross-linking with 125I-IGF-I, migrated as specific reduced bands of Mr = 138,000 during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The subunit sizes of the B-2 reactive IGF-I receptor were similar to those of the insulin receptor. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of 125I-labeled receptors immunoprecipitated by autoantiserum B-2 or autoantiserum B-10 (which recognizes only insulin receptors) revealed, in both cases, specific reduced bands of Mr = 130,000 and 90,000; the same bands were also seen after sequential precipitation with B-10 and B-2 antisera to enrich the proportion of IGF-I receptors recovered. The presence of two distinct binding and immunoreactive species of IGF-I receptors in human placenta raises the possibility that cell- or tissue-specific isotypes of the IGF-I receptor could mediate the different biological actions of IGF-I.     

The pectoralis minor vascularized muscle graft for the treatment of unilateral facial palsy

A series of 10 pectoralis minor vascularized muscle transfers to reanimate the face in unilateral facial palsy are presented. The procedure is carried out in two stages. The first stage constitutes a nerve graft from the functional contralateral facial nerve to the preauricular region of the paralyzed side. Six months later, the pectoralis minor is transferred to the denervated side of the face with restoration of its neurovascular pedicle. The muscle is well suited to its new position with respect to length and bulk, as well as its fanlike shape. The diameter of its vascular pedicle is comparable with the facial vessels. The results demonstrate function in 8 of the 10 grafts, the two failures relating to early vascular thrombosis rather than an inability to reinnervate the muscle grafts.     

Elaborations of the basal surface of the cells of the Malpighian tubules of an insect

Electrical measurements of membrane potential and resistance using intracellular microelectrodes showed that the fluid-secreting parts of the Malpighian tubules of Rhodnius have superficial regions different in electrical properties from the main body of the cell. The membrane potential in these superficial regions was smaller by 30-40 mV, but showed a standard depolarization on changing the potassium concentration of the bathing medium. The response to changes in the external chloride concentration also differed in the two regions, a finding that was reinforced by different responses to the drug, furosemide. Electron microscopy of the basal regions of the cells revealed many long cellular projections that run parallel to the cell surface and interdigitate with similar projections from neighbouring cells. The degree of interdigitation was examined by marking individual cells with alcian blue or by horseradish peroxidase injection. A survey of the published micrographs of insect Malpighian tubules shows that most have similar projections on their basal surfaces and not the simple basal infoldings previously supposed.     

Sperm parameters and testicular volumes in Saguinus mystax

Adult male Saguinus mystax tamarins were evaluated for sperm parameters and testicular volumes. Sperm concentrations average 195.5 X 10(6)/cc with 41.7% motile sperm. Semen specimens were classified as normal, relative to sperm morphology, when 95% or more of the sperm in the specimen had normal morphology; 76% of the animals evaluated had normal semen specimens using this criterion. Testicular volumes averaged 726.9 mm3. A total of 50 infants were sired by 16 of these males during the period covered by this report.     

Headache at high altitude is not related to internal carotid arterial blood velocity

The cause of headache in persons going to high altitude is unknown. Relatively severe hypoxemia in susceptible subjects could induce large increases in cerebral blood flow that then could initiate the headache. Thus we measured noninvasively, by Doppler ultrasound, changes in internal carotid arterial blood velocity (velocity) in 12 subjects in Denver (1,600 m) and repeatedly up to 7 h at a simulated altitude of 4,800 m (barometric pressure = 430 Torr). Six subjects, selected because of prior history of high-altitude headache, developed comparatively severe headache at 4,800 m, and four subjects, without such history, remained well. Two subjects developed moderate headache. Velocity at 4,800 m did not correlate with symptom development, arterial O2 saturation, or end-tidal PCO2. Also, neither velocity nor blood pressure was consistently elevated above the Denver base-line values. During measurements of hypercapnic ventilatory response in Denver, velocity increased linearly with end-tidal PCO2, confirming that our Doppler method could demonstrate an increase. Also, 30 min of isocapnic or poikilocapnic hypoxia caused small increases in velocity (+8 and +6%) during the base-line measurement at low altitude. Although even a small increase in cerebral perfusion could contribute to headache symptoms at high altitude, cerebral blood flow does not appear to play a primary role.     

Emergence of some caddisflies (Trichoptera) from a wooded stream in southern Ontario

Twenty-eight species of nine families of caddisflies (Trichoptera) were identified in 170 samples taken over an 8-month period from five emergence traps placed on a second-order, forested, cold-stenothermal stream on the Niagara Escarpment, Ontario, Canada.A mean of 980.9 caddisflies m^–2 of streambed was obtained over the entire sampling period. Eleven common species accounted for 92.8% of the total emergence with specific proportions ranging from 23.8% (Wormaldia moesta) to 0.11 % (Rhyacophila sp.). The use of various kinds of traps in other studies and their effects on the detection of species composition and abundance are discussed and compared with the present study.Although the distributions of all the common species were invariant over time, four species showed low to high degrees of patchiness in the streambed; the other seven common species were uniformly distributed. However, a large residual variance suggested a subtle mechanism of microhabitat selection by the larvae and (or) pupae, not detectable by even the small emergence traps used.Both sexes of 15 species, only males of 4 and only females of 9 species were collected. Eight of the eleven common species showed significant departures from a balanced sex ratio and five exhibited a protandry of from 1 to 3 weeks. Neither this study nor others have been able to establish a predictable pattern of sex ratios in Trichoptera.The emergence periods and patterns of the eleven common species are described and compared with other studies. Of these common species, one emerged in the spring, seven during the summer and three during the late summer or early fall. Ten species had a short emergence period with a distinct peak and a significantly skewed pattern. One species,Parapsyche apicalis, exhibited a prolonged emergence period, no distinct peak and a significantly platykurtotic² pattern. With the exception ofLepidostoma sp. A, the emergence patterns of the common species were unimodal.