Conservation of absolute foveal area in New World monkeys. A constraint on eye size and conformation

The foveal specializations of five New World monkeys, the marmoset, Callithrix jacchus; the golden-handed tamarin, Saguinus midas niger; the squirrel monkey, Saimiri ustius; the capuchin monkey, Cebus apella; and the howler monkey, Alouatta caraya were compared. Although retinal area varies by over a factor of two in these monkeys, the area of the fovea does not covary with retinal area and remains approximately the same absolute size, as measured by the dimensions of the high density region of cones, or the rod-free region. This constancy in foveal size also holds for rhesus monkeys and humans, bringing the variation in retinal area to a factor of five. Alouatta caraya is unusual, distinguished by a very high central cone density and a small rod-free zone. Physiological constraints that might limit foveal area over a wide range of eye sizes are considered.     

Guanosine and GMP prevent seizures induced by quinolinic acid in mice

In the mammalian CNS, glutamate and GABA are the principal neurotransmitters mediating excitatory and inhibitory synaptic events, respectively, and have been implicated in the neurobiology of seizures. Guanine-based purines, including the nucleoside guanosine and the nucleotide GMP, have been shown to antagonize glutamatergic activity at the receptor level and the other purine nucleoside adenosine is a well-known modulator of seizure threshold. In the present study we investigated the anticonvulsant effect of i. p. guanosine and GMP against seizures induced by the glutamate agonist quinolinic acid (QA) or the GABA(A) antagonist picrotoxin in mice. Animals were pretreated with an i.p. injection of saline, guanosine or GMP 30 min before either an i.c.v. injection of 4 microliter QA (36.8 nmol) or a subcutaneous injection of picrotoxin (3.2 mg/kg). All animals pretreated with vehicle followed by QA or picrotoxin presented seizures, which were completely prevented by the NMDA antagonist MK-801 and the GABA agonist phenobarbital, respectively. Guanosine and GMP dose-dependently protected against QA-induced seizures, up to 70 and 80% at 7.5 mg/kg, with ED(50)=2. 6+/-0.4 and 1.7+/-0.6 mg/kg, respectively. Conversely, neither guanosine, GMP nor MK-801 affected picrotoxin-induced seizures, indicating some degree of specificity towards the glutamatergic system. This study suggests anticonvulsant properties of i.p. guanosine and GMP, which may be related with antagonism of glutamate receptors.     

Trace element determination of Argentine wines using ETAAS and USN-ICP-OES.

The objective of this work was to develop a method to determine the metal content in wine samples from the province of Mendoza in Argentina. Ten samples of white wine and 10 samples of red wine available in the supermarket were analyzed for the metals aluminium, cadmium, calcium, chromium, copper, iron, nickel, lead and zinc by electrothermal atomic spectrometry (ETAAS) and ultrasonic nebulization was coupled to inductively coupled plasma optical emission spectrometry (USN-ICP-OES). The aluminium, cadmium, calcium, copper, iron, lead, zinc, chromium concentrations were between 17.0-18.0 microg l(-1), 1.0-4.7microg l(-1), 10.0-15.0 mg l(-1), 23.0-28.0 microg l(-1), 480-790 microg l(-1), 50-90 microg l(-1), 24-130 microg l(-1), and <0.2-6.25 microg l(-1), respectively. The levels compare well with those reported for similar wines from some other parts of the world. A significant aspect in this paper is the samples mineralization step, which allowed the direct determination of the metals. Concerning to the Cd determination, a refluxing digestion system was used for the pretreatment of the samples.     

The cyclin-dependent kinase inhibitor UCN-01 plus cisplatin in advanced solid tumors: a California cancer consortium phase I pharmacokinetic and molecular correlative trial.

BACKGROUND: UCN-01 (7-hydroxy-staurosporine) is a novel antineoplastic agent targeting cyclin-dependent kinases, which shows potent in vitro and in vivo activity against a broad range of tumor types. Our group has previously shown that UCN-01 potentiates the apoptotic response of agents such as cisplatin in vitro by preventing sequence-specific abrogation of G2 arrest caused by DNA-damaging chemotherapies. PATIENTS AND METHODS: This National Cancer Institute-sponsored phase I trial was designed to determine the safety, maximum tolerated dose, and pharmacokinetics of escalating doses of cisplatin in combination with UCN-01 in patients with advanced malignant solid tumors, as well as to do molecular correlative studies on tumor specimens. Cisplatin was infused over 1 hour before UCN-01 (45 mg/m2/d) given as a 72-hour continuous infusion. Escalation of cisplatin was planned through five dose levels at 20, 30, 45, 60, and 75 mg/m2. RESULTS: Ten patients were accrued. Accrual was halted at dose level 2 (cisplatin, 30 mg/m2) due to dose-limiting toxicities consisting of grade 5 sepsis with respiratory failure associated with grade 3 creatinine (one patient) and grade 3 atrial fibrillation (one patient). Plasma and salivary pharmacokinetics of UCN-01 were unaffected by cisplatin. Pretreatment and posttreatment tumor biopsies showed that UCN-01 was active against a key molecular target, the checkpoint kinase Chk1.CONCLUSIONS: This phase I trial failed to achieve targeted therapeutic dose levels of cisplatin when combined with prolonged infusion UCN-01. However, because preclinical data indicate that UCN-01 potentiates response to platinum, further studies with alternative dose schedules of the combination, or with other platinum analogues, are warranted.     

Evaluation of a preoperative multimedia information program in surgical oncology.

AIM: We report on the design, validation and evaluation of a DVD for patient information in a department of surgical oncology. PATIENTS AND METHOD: DVDs provided the patient with information about the anatomy, surgical techniques and post-operative complications on digestive cancers, oral cavity and breast tumours. After surgery a questionnaire was sent to the patients in order to evaluate their level of satisfaction and opinion regarding the pre-operative information they had been given. RESULTS: One hundred and eight patients were invited to watch the DVD. Seventy-one percent of the patients considered that viewing the DVD had been positive and encouraging and 83% of all the patients would recommend its use. Among the 14 patients who experienced complications, only 21% declared having been well informed by the DVD and only 12% considered they were better prepared to face those complications. CONCLUSIONS: DVD based information systems are valuable and acceptable to patients, but the presentation of complications needs to be improved.