Molt induction in lobsters (Homarus americanus) by intramuscular injection of ecdysterone triacetate

The principal component of the successful, molt-inducing ecdysterone acetate mixture was established as ecdysterone triacetate and shown to have the same activity as the acetate mixture. The triacetate induced ecdysis in male lobsters collected in winter and summer and in female lobsters collected in winter. Intramuscular injections of triacetate in ethanol were as effective as those with oil emulsions.     

Formation of an activated N-nitroso compound in nitrite-treated fava beans (Vicia faba)

Fava beans are prominent in the diet of the Colombian population at high gastric cancer risk. Upon nitrite treatment under simulated gastric conditions, a potent mutagen was formed as detected by a forward mutation assay using Salmonella typhimurium TM677 without microsomal activation. The promutagen was partially purified by preparative t.l.c. and normal phase h.p.l.c. of the acetone-soluble portion of a dried aqueous extract. The nitrosated promutagen fully accounted for the mutagenicity observed with whole fava beans. One gram of fresh fava beans yielded approximately 0.35 nmol of mutagen. Mutagenicity data indicated that this mutagen was more potent than N-methyl-N'-nitro-N-nitrosoguanidine. The characteristics of the mutagen were typical of an activated N-nitroso compound, that is a compound in which the N-nitroso moiety is attached to an activating group, such as a carbonyl group. Irradiation of the mutagen yielded a Griess positive reaction. By reverse-phase h.p.l.c. photohydrolysis, a single peak could be ascribed to the mutagen. Its stability varied as a function of pH, being most unstable under alkaline conditions. Cysteine and phosphate concentration had no effect on its rate of decomposition, thereby strongly suggesting that the mutagen is an N-nitrosourea. The results obtained in this study support the hypothesis of carcinogenesis via the intragastric production of activated N-nitroso compounds.     

Palliative effect of metaiodobenzylguanidine in metastatic carcinoid tumors

PURPOSE: To evaluate the therapeutic effect of iodine-131-labeled metaiodobenzylguanidine (131I-MIBG) and unlabeled MIBG in patients with carcinoid tumor. MATERIALS AND METHODS: A therapeutic dose of 7.4 GBq (200 mCi) 131I-MIBG infused over 4 hours was administered to 30 patients with either carcinoid syndrome (n = 20) or tumor symptoms such as pain and fever due to carcinoid tumor (n = 10). In general, two courses were given, 6 weeks apart. Due to radioactivity, patients had to be isolated for 5 to 7 days. Subsequently, we studied the effect of unlabeled MIBG based on the possible pharmaceutic activity of MIBG and to avoid the isolation procedure. A doseescalation study of 8.5, 17, and 34 mg/m2 MIBG infused over 4 hours at 4-week intervals was performed in 20 patients with carcinoid syndrome who were not suitable for treatment with the radioactive compound. RESULTS: Following 131I-MIBG treatment, symptomatic responses were observed in 60% of patients (median duration, 8 months; maximum, 2 years). Side effects were mild and rapidly reversible in 16 patients, and were related to the isolation procedure in seven of these patients. Unlabeled MIBG resulted in symptomatic improvement in 60% of patients (median duration, 4.5 months). Side effects, which included changes in blood pressure, were mild and transient. Symptomatic responses were not accompanied by biochemical responses. CONCLUSION: Both MIBG treatment regimens were equally effective in the palliation of symptoms, but duration of response tended to be much longer with the radioactive compound. However, the unlabeled compound provided a simpler treatment, eg, in elderly patients and those in poor condition, without the need for isolation.     

Traumatic aortic rupture: diagnosis and management

BACKGROUND: Traumatic aortic rupture is a relatively uncommon lesion that presents the cardiothoracic surgeon with unique challenges in diagnosis and management. To address controversial aspects of this disease, we reviewed our experience. METHODS: The study was performed by retrospective chart review. RESULTS: Forty-two patients with traumatic thoracic aortic ruptures were managed between January 1988 and June 1997. Nine arrived without vital signs and died in the emergency department. Admission chest radiographs were normal in 3 patients (12%) and caused significant delays in diagnosis. Four of 30 patients admitted with vital signs had rupture before thoracotomy and died. Twenty-six underwent aortic repair. In 1 patient repair was performed with simple aortic cross-clamping, whereas a second was managed with a Gott shunt. The remaining 24 patients had repair with partial left heart bypass. In 1 patient hypothermic circulatory arrest was required. Two patients (7.7%) died. There were no cases of new postoperative paraplegia in the bypass group. There was no morbidity directly attributable to the administration of heparin for cardiopulmonary bypass. CONCLUSIONS: In a discrete group of patients with traumatic rupture of the aorta, the rupture will become complete during the first few hours of hospital admission; aggressive medical treatment with beta-blockade and vasodilators in the interval before the operation is an essential aspect of management. Active distal circulatory support with partial left-heart bypass provides the optimal means of preventing spinal cord ischemia during repair of acute traumatic aortic rupture.     

The impact of metformin therapy on hepatic glucose production and skeletal muscle glycogen synthase activity in overweight type II diabetic patients

The effect of metformin therapy on glucose metabolism was examined in eight overweight newly presenting untreated type II diabetic patients (five males, three females). Patients were treated for 12 weeks with either metformin (850 mg x 3) or matching placebo using a double-blind crossover study design; patients were studied at presentation and at the end of each treatment period. Insulin action was assessed by measuring activation of skeletal muscle glycogen synthase (GS) before and during a 4-hour hyperinsulinemic euglycemic clamp (100 mU.kg-1 x h-1). Metformin therapy was associated with a significant decrease in fasting blood glucose (6.8 +/- 0.6 v 8.3 +/- 0.9 mmol.L-1, P < .01) and glycosylated hemoglobin ([HbA1] 7.7% +/- 0.4% v 8.5% +/- 0.5%, P < .01) levels. Fasting hepatic glucose production (HGP) was also significantly decreased following metformin therapy (1.98 +/- 0.13 v 2.41 +/- 0.20 mg.kg-1 x min-1, P < .02), whereas fasting insulin and C-peptide concentrations remained unaltered. The decrease in basal HGP correlated closely with the decrease in fasting blood glucose concentration (r = .92, P < .001). Insulin-stimulated glucose uptake was assessed using the hyperinsulinemic euglycemic clamp technique and was increased post-metformin (3.8 +/- 0.6 v 3.1 +/- 0.7 mg.kg-1 x min-1, P < .05). This was primarily the result of increased nonoxidative glucose metabolism (1.1 +/- 0.6 v 0.4 +/- 0.6 mg.kg-1 x min-1, P < .05); oxidative glucose metabolism did not change. Metformin had no measurable effect on insulin activation of skeletal muscle GS, the rate-limiting enzyme controlling muscle glucose storage.(ABSTRACT TRUNCATED AT 250 WORDS)     

EGF-induced redistribution of erbB2 on breast tumor cells: flow and image cytometric energy transfer measurements

The effects of the CCK(B) antagonists, CAM1028 and CI988 and a CCK(A) antagonist, CAM1481, were studied on the anxiety-related behaviour produced by withdrawal from chronic ethanol treatment, using the elevated plus maze. Cessation of chronic ethanol administration produced a profile, in both mice and rats, consistent with increase in anxiety-related behaviour. In mice, SC administration of CAM1028 or CI988 reduced the decrease in the time spent on the open arms, the number of entries into these arms and the increases in the latencies to first open arm entry, after withdrawal from the ethanol treatment. The increases in stretched attend postures and head dips from the closed arms and the central square seen during the withdrawal phase, were also decreased by the CCK(B) antagonists, but the decreases in the number of rears and in general activity were unaffected. The doses of CAM1028 and CI988 tested were 0.1 and 1 mg/kg; for some of the withdrawal-induced changes in behaviour only the 1 mg/kg dose was effective. In contrast, the CCK(A) antagonist, CAM1481, at the same doses, had little effect on the anxiety-related behaviour produced by withdrawal from chronic ethanol treatment, although it did decrease the changes in the number of rears and the head dipping behaviour. In rats, the majority of the changes produced by withdrawal from chronic ethanol treatment were decreased by CAM1028 at 1 mg/kg, although the decreases in open arm entries, rearing behaviour and in overall activity were unaffected. CAM1028, CI988 and CAM1481 had no effects on the behaviour of control mice or rats in the plus-maze. The results show that CCK(B) antagonists were effective in decreasing the majority of the anxiogenic effects of withdrawal from chronic ethanol treatment.     

Liposomal daunorubicin in advanced Kaposi's sarcoma: a phase II study

We report a non-randomized Phase II clinical trial to assess the efficacy and safety of liposomal daunorubicin (DaunoXome) in the treatment of AIDS related Kaposi's sarcoma. Eleven homosexual men with advanced Kaposi's sarcoma were entered in the trial. Changes in size, colour and associated oedema of selected 'target' lesions were measured. Clinical, biochemical and haematological toxicities were assessed. Ten subjects were evaluated. A partial response was achieved in four, of whom two subsequently relapsed. Stabilization of Kaposi's sarcoma occurred in the remaining six, maintained until the end of the trial period in four. The drug was generally well tolerated, with few mild symptoms of toxicity. The main problem encountered was haematological toxicity, with three subjects experiencing severe neutropenia (neutrophil count < 0.5 x 10(9)/l). There was no evidence of cardiotoxicity. In this small patient sample, liposomal daunorubicin was an effective and well tolerated agent in the treatment of Kaposi's sarcoma.     

Sequences of the coat protein gene of five peanut stripe virus (PStV) strains from Thailand and their evolutionary relationship with other bean common mosaic virus sequences

The coat protein gene and part of the 3' non-coding region of five strains of peanut stripe virus (PStV) from Thailand have been cloned and sequenced. Phylogenetic comparisons of these strains, known as T1, T3, T5, T6 and T7, and related sequences showed that these strains are indeed strains of PStV. Further, PStV strains appear to be related to each other according to their geographic origin. That is, the Thai strains are more closely related to each other than they are to strains from the USA or Indonesia, despite the variety of symptoms caused by these strains and the overlap of symptom types between the strains from different locations. Like other PStV strains, PStV-Thai can be considered strains of bean common mosaic virus (BCMV) but can be distinguished from bean-infecting strains of BCMV and blackeye cowpea mosaic virus (B1CMV) through sequence and host range. No evidence was found that PStV-Thai strains, unlike PStV-Ib, are recombinants of PStV and B1CMV, although the T3 strain may be a recombinant of different PStV sequences. Phylogenetic analyses of viruses of the BCMV group suggest that acquisition of the ability to infect peanut may have occurred only once.