Circulating melanoma-associated antigens in ocular melanoma

A pilot study was performed to test for melanoma-associated antigens (MAAgs) in the sera of patients with localized uveal melanoma, using monoclonal antibodies (MoAbs). Both whole sera and polyethylene glycol (PEG) 2.5% serum precipitates from 18 patients with clinically localized uveal melanoma and two patients with localized invasive conjuctival melanoma were analyzed for two human cutaneous MAAgs by an enzyme-linked immunosorbent assay (ELISA). These antigens could not be identified when whole sera were used. However, after PEG precipitation, a MoAb specific for the p210 MAAg reacted with four of 20 patient samples and none of 17 controls. A second MoAb specific for the p97a MAAg reacted with one of 20 patients and none of 17 controls. These findings indicate the existence of antigens common to both uveal and cutaneous melanoma and suggest that the refinement of assays to screen sera with a battey of MoAbs may be of value in diagnosing and/or monitoring patients with uveal melanoma. Circulating immune complexes were detected in the sera of six patients but did not correlate with any clinical features or with the presence or absence of detectable MAAgs.     

Acute Exposure to the Mitochondrial Complex I Toxin Rotenone Impairs Synaptic Long‐Term Potentiation in Rat Hippocampal Slices

Aims: To evaluate the acute effects of the mitochondrial complex I inhibitor rotenone on rat hippocampal synaptic plasticity. Methods: Electrophysiological field potential recordings were used to measure basal synaptic transmission and synaptic plasticity in rat coronal hippocampal slices. Synaptic long‐term potentiation (LTP) was induced by high‐frequency stimulation (100 Hz, 1 second × 3 at an interval of 20 seconds). In addition, mitochondrial complex I function was measured using MitoSOX imaging in mitochondrial preparations. Results: Acute exposure of hippocampal slices to 50 nM rotenone for 1 h did not alter basal CA3–CA1 synaptic transmission though 500 nM rotenone significantly reduced basal synaptic transmission. However, 50 nM rotenone significantly impaired LTP and this rotenone's effect was prevented by co‐application of rotenone plus the ketones acetoacetate and β‐hydroxybutyrate (1 mM each). Finally, we measured mitochondrial function using MitoSOX imaging in mitochondrial preparations and found that 50 nM rotenone partially reduced mitochondrial function whereas 500 nM rotenone completely eliminated mitochondrial function. Conclusions: Our findings suggest that mitochondrial activity driven by complex I is a sensitive modulator of synaptic plasticity in the hippocampus. Acute exposure of the hippocampus to rotenone eliminates complex I function and in turn impairs LTP.     

Orbital extension of retinoblastoma: a clinicopathological study

We have studied all cases of orbital extension of retinoblastomas at the Edward S. Harkness Eye Institute in New York since 1925. Only 9.4% of the patients lived more than 2 years after diagnosis. Orbital retinoblastoma is frequently associated with systemic metastases. We emphasize the significance of massive choroidal involvement and periemissarial extension. Careful handling of the enucleation specimen at the time of surgery and during histologic preparation is important to avoid cell spillage and artifacts. Treatment should be early, multidisciplinary and include adjuvant chemotherapy.     

Correlation of Levels and Patterns of Genomic Instability With Histological Grading of DCIS

BACKGROUND: Histological grading of ductal carcinoma-in-situ (DCIS) lesions separates DCIS into three subgroups (well-, moderately, or poorly differentiated). It is unclear, however, whether breast disease progresses along a histological continuum or whether each grade represents a separate disease. In this study, levels and patterns of allelic imbalance (AI) were examined in DCIS lesions to develop molecular models that can distinguish pathological classifications of DCIS. METHODS: Laser microdissected DNA samples were collected from DCIS lesions characterized by a single pathologist including well- (n = 18), moderately (n = 35), and poorly differentiated (n = 47) lesions. A panel of 52 microsatellite markers representing 26 chromosomal regions commonly altered in breast cancer was used to assess patterns of AI. RESULTS: The overall frequency of AI increased significantly (P < .001) with increasing grade (well differentiated, 12%; moderately differentiated, 17%; poorly differentiated, 26%). Levels of AI were not significantly different between well- and moderately differentiated grades of disease but were significantly higher (P < .0001) in poorly differentiated compared with well- or moderately differentiated disease. No statistically significant differences in patterns of AI were detected between well- and moderately differentiated disease; however, AI occurred significantly more frequently (P < .05) in high-grade lesions at chromosomes 6q25-q27, 8q24, 9p21, 13q14, and 17p13.1, and significantly more frequently in low-grade lesions at chromosome 16q22.3-q24.3. CONCLUSIONS: The inability to discriminate DCIS at the genetic level suggests that grades 1 and 2 DCIS may represent a single, non-high-grade form of DCIS, whereas poorly differentiated DCIS seems to be a genetically more advanced disease that may represent a discrete disease entity, characterized by a unique spectrum of genetic alterations.     

Species and functional group diversity independently influence biomass accumulation and its response to CO2 and N

The characteristics of plant assemblages influence ecosystem processes such as biomass accumulation and modulate terrestrial responses to global change factors such as elevated atmospheric CO(2) and N deposition, but covariation between species richness (S) and functional group richness (F) among assemblages obscures the specific role of each in these ecosystem responses. In a 4-year study of grassland species grown under ambient and elevated CO(2) and N in Minnesota, we experimentally varied plant S and F to assess their independent effects. We show here that at all CO(2) and N levels, biomass increased with S, even with F constant at 1 or 4 groups. Likewise, with S at 4, biomass increased as F varied continuously from 1 to 4. The S and F effects were not dependent upon specific species or functional groups or combinations and resulted from complementarity. Biomass increases in response to CO(2) and N, moreover, varied with time but were generally larger with increasing S (with F constant) and with increasing F (with S constant). These results indicate that S and F independently influence biomass accumulation and its response to elevated CO(2) and N.     

Is gonadotrope expression of the gonadotropin releasing hormone receptor gene mediated by autocrine/paracrine stimulation of an activin response element?

Expression of the FSHbeta subunit and GnRH receptor (GnRHR) genes in gonadotropes is stimulated by activin. We sought to identify the cis-acting element(s) in the murine GnRHR gene promoter which confer activin responsiveness. We established that 600 bp of 5'flanking sequence from the murine GnRHR gene were sufficient to confer activin responsiveness in the gonadotrope-derived alphaT3-1 cell line. Since alphaT3-1 cells, like gonadotropes, secrete activin, we examined the ability of follistatin, an activin binding protein, to block the activin response. Increasing concentrations of follistatin from 0 to 100 ng/ml resulted in a dose dependent decrease in activity of the -600 promoter. Contained within this region are three elements important for expression in alphaT3-1 cells: a Steroidogenic Factor-1 binding site (SF-1), an Activator Protein-1(AP-1) element, and an element termed the GnRH receptor activating sequence or GRAS. A block mutation of GRAS inhibited the ability of the promoter to respond to follistatin. A more refined analysis using a series of two-bp mutations which scan GRAS and flanking sequence revealed exact convergence of GRAS with activin/follistatin responsiveness. Finally, a construct consisting of 3 copies of GRAS placed upstream of a heterologous minimal promoter (3xGRAS-PRL-LUC) was responsive to both activin stimulation and follistatin inhibition in alphaT3-1 cells. Thus, autocrine/paracrine stimulation of gonadotropes by activin illustrates a unique mechanism for cell-specific gene expression.     

The role of gonadal steroids in feedback regulation of gonadotropin secretion at different stages of primate development

The serum gonadotropin response to castration was assessed in 8 foetal, 2 neonatal, 30 juvenile, and 2 adult rhesus monkeys (M. mulatta). In the 30 castrated juvenile monkeys and 8 sham-operated controls, concentrations of oestrone, oestradiol, androstenedione, dihydrotestosterone, testosterone and 17OH-progesterone were measured in 10 ml serum pools before, one month after, and one year after the surgical procedure. Castration during foetal life (83-137 days gestation) was followed within 48-72 h by a significant rise in serum FSH levels in males, but had no effect on the already high levels in females. Similarly, castration of males during the first post-natal month raised serum FSH and LH into the adult castrate range; however, after 3 months of age serum gonadotropin levels again declined to the normal juvenile range in spite of the open feedback loop. Orchiectomy of prepubertal juvenile monkeys (age 3 month-2 8/12 years) had no immediate effect on serum gonadotropins, but was followed by a delayed rise in FSH (at age 2 3/12-4 3/12 years) and LH (at age 2 7/12-4 4/12 years) to adult castrate levels. Orchiectomy of older prepubertal (by serum testosterone) or adult males resulted within a few days in a progressive and sustained rise in serum FSH and a more gradual rise in LH. Prepubertal gonadotropin regulation appeared to be sexually dimorphic, since ovariectomy in juvenile females (age 3 months-1 5/12 years) was followed by generally elevated, if somewhat erratic, serum FSH values, with a secondary rise in both FSH and LH levels at 2-2 1/12 years. In both sexes, prepubertal castration caused a significant and sustained decline in serum concentrations of oestradiol; castrated males also showed a decline in serum testosterone levels. Although prepubertal castration also caused in both sexes a slight decline in serum oestrone, and ovariectomy a decline in serum androstenedione and dihydrotestosterone, these effects were not sustained one year later, and values were not significantly different from sham-operated controls. Taken together, these data lend support to a model of primate sexual maturation in which the primary regulator of gonadotropin secretion in both sexes during the prolonged juvenile phase is central inhibition of the hypothalamic GnRH regulator. However, during foetal and neonatal life, and again following the onset of puberty, the major modulator of gonadotropin secretion becomes sex steroid-mediated feedback inhibition.     

From the Cover: Transgenic cotton and sterile insect releases synergize eradication of pink bollworm a century after it invaded the United States

Invasive organisms pose a global threat and are exceptionally difficult to eradicate after they become abundant in their new habitats. We report a successful multitactic strategy for combating the pink bollworm (Pectinophora gossypiella), one of the world’s most invasive pests. A coordinated program in the southwestern United States and northern Mexico included releases of billions of sterile pink bollworm moths from airplanes and planting of cotton engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). An analysis of computer simulations and 21 y of field data from Arizona demonstrate that the transgenic Bt cotton and sterile insect releases interacted synergistically to reduce the pest’s population size. In Arizona, the program started in 2006 and decreased the pest’s estimated statewide population size from over 2 billion in 2005 to zero in 2013. Complementary regional efforts eradicated this pest throughout the cotton-growing areas of the continental United States and northern Mexico a century after it had invaded both countries. The removal of this pest saved farmers in the United States $192 million from 2014 to 2019. It also eliminated the environmental and safety hazards associated with insecticide sprays that had previously targeted the pink bollworm and facilitated an 82% reduction in insecticides used against all cotton pests in Arizona. The economic and social benefits achieved demonstrate the advantages of using agricultural biotechnology in concert with classical pest control tactics.

Invasive life forms pose a major global threat and are especially difficult to eradicate after they become widespread and abundant in their new habitats (1–4). The pink bollworm (Pectinophora gossypiella), one of the world’s most invasive insects, is a voracious lepidopteran pest of cotton that was first detected in the United States in 1917 (5–8). For most of the past century, it was particularly destructive in the southwestern United States, including Arizona, where its larvae fed almost exclusively on cotton, consuming the seeds inside bolls and disrupting lint production (6, 8). In 1969, its peak seasonal density at an Arizona study site was 1.8 million larvae per hectare (ha), which translates to over 200 billion larvae in the 126,000 ha of cotton planted statewide that year (9, 10). In 1990, this pest cost Arizona cotton growers $48 million, including $32 million damage to cotton despite $16 million spent for insecticides sprayed to control it (11). In several field trials, mass releases of sterile pink bollworm moths to mate with wild moths reduced progeny production somewhat, yet did not suppress established populations because the sterile moths did not sufficiently outnumber the wild moths (6, 12–14).Pink bollworm control was revolutionized in 1996 by the introduction of cotton genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Bt proteins kill some major insect pests yet are not toxic to most nontarget organisms, including people and many beneficial insects (15–17). Transgenic Bt cotton helped to reduce the total annual cost of pink bollworm damage and insecticide treatments to $32 million in the United States (18). Although Bt cotton kills essentially 100% of susceptible pink bollworm larvae (19–21), this pest rapidly evolved resistance to Bt proteins in laboratory selection experiments in Arizona and in Bt cotton fields in India (20–24). To delay the evolution of resistance to Bt cotton, farmers in Arizona planted “refuges” of non-Bt cotton that yielded abundant susceptible moths to mate with the rare resistant moths emerging from Bt cotton (Fig. 1A). The refuge strategy, which has been mandated in the United States and many other countries, but was not adopted widely by farmers in India, helped preserve pink bollworm susceptibility to Bt cotton in Arizona from 1996 to 2005 (24).Open in a separate windowFig. 1.Management strategies. (A) The refuge strategy is the primary approach adopted worldwide to delay the evolution of pest resistance to Bt crops and was used in Arizona from 1996 to 2005. Refuges of non-Bt cotton planted near Bt cotton produce abundant susceptible moths (blue) to mate with the rare resistant moths (red) emerging from Bt cotton. If the inheritance of resistance to Bt cotton is recessive, as in pink bollworm, the heterozygous offspring from matings between resistant and susceptible moths die when they feed on Bt cotton bolls as larvae (24). (B) Bt cotton and sterile moth releases were used together in Arizona from 2006 to 2014 as part of a multitactic program to eradicate the pink bollworm. Susceptible sterile moths (brown) were released from airplanes to mate with the rare resistant moths emerging from Bt cotton. The few progeny produced by such matings (48) are expected to be heterozygous for resistance and to die when they feed on Bt cotton bolls as larvae.As part of a coordinated, multitactic effort to eradicate the pink bollworm from the southwestern United States and northern Mexico, a new strategy largely replacing refuges with mass releases of sterile pink bollworm moths was initiated in Arizona during 2006 (Fig. 1B; 24–27). To enable this novel strategy, the US Environmental Protection Agency granted a special exemption from the refuge requirement, which allowed Arizona cotton growers to plant up to 100% of their cotton with Bt cotton (28). We previously reported data from 1998 to 2009 showing that this innovative strategy sustained susceptibility of pink bollworm to Bt cotton while reducing the pest’s population density (25). Here, to test the idea of eradicating pink bollworm with the combination of Bt cotton and sterile releases, we conducted computer simulations and analyzed field data collected in Arizona from 1998 to 2018.