18F-labeling and biodistribution of the novel fluoro-quinolone antimicrobial agent, trovafloxacin (CP 99,219)

[18F]CP 99,219 [(1 alpha, 5 alpha, 6 alpha)-7-(6-amino-3-azabicyclo [3.1.0]hex-3-yl)-1-(2,4-difluorophenyl)-6-fluoro-1, 4-dihydro-4-oxo-1, 8-naphthyridine-3-carboxylic acid] was prepared by 18F for 19F exchange followed by reverse-phase HPLC purification. Studies of the effects of reaction time and temperature on 18F incorporation demonstrated that heating 1.0 mg of CP 99,219 in 0.5 cc of DMSO with 4.5 mg of K2CO3 and 24 mg of Kryptofix for 15 min at 160 degrees C results in the optimal compromise between radiochemical yield and purity. This method routinely provides radiochemical yields of 15-30% [EOS] with radiochemical purities of > 97%. Varying the concentration of CP 99,219 in the reaction mixture had no effect on yield. Biodistribution studies in rats demonstrated that significant concentrations of drug accumulate in most tissues. The tissues with the highest concentrations of drug were intestine, liver, kidney, and stomach.

Partial exchange transfusion in the treatment of severe falciparum malaria

BACKGROUND

Exchange transfusion as an adjunct to the treatment of severe falciparum malaria has been widely recommended, although there is no well-designed clinical trial to prove its efficacy. The amount of compatible blood required for total exchange is rarely available in areas endemic for malaria and the risks of the procedure including transfusion-related infections are high.

METHODS

Partial transfusion with four units of blood was given to a patient with severe falciparum malaria (80% parasitaemia) whose condition deteriorated on conventional treatment with intravenous quinine.

RESULTS

This brought about prompt clinical improvement and reduction in parasitaemia.

CONCLUSION

Partial transfusion with one or two litres of blood is a promising and viable alternative to total exchange transfusion.

Assessing pre-procedural subgingival irrigation and rinsing with an antiseptic mouthrinse to reduce bacteremia

In this controlled clinical study, the authors examined the effect of subgingival irrigation and rinsing with an antiseptic mouthrinse before ultrasonic scaling of a quadrant containing inflamed gingivae. The results showed that pre-procedural subgingival irrigation and rinsing can significantly reduce the level of bacteremia associated with ultrasonic scaling. These results support the American Heart Association's recommendation of adjunctive subgingival irrigation prior to invasive procedures in patients at risk of developing bacterial endocarditis.

Seroprevalence of five arboviruses in Zebu cattle in the Central African Republic

Sequential blood samples taken from 237 adult and 147 young Zebu cattle in the Central African Republic (CAR) were examined by enzyme-linked immunosorbent assay for the presence of antibodies to Rift Valley Fever (RVF), Dugbe (DUG), Crimean-Congo haemorrhagic fever (CCHF), Chikungunya (CHIK) and Wesselsbron (WSL) viruses. Antibodies to DUG and CCHF viruses were detected in 70% and 61% respectively, of the sera from adult cattle, probably due to common antigens. This hypothesis is supported by the fact that CCHF virus was isolated only 3 times from ticks, whereas DUG virus was isolated from almost all ticks. Ticks of the genus Hyalorama, the most important vectors of CCHF, are rare on Zebus in CAR. CCHF virus has a limited role in local human pathology, probably because its distribution is limited by the scarcity of its main vector and the immunological barrier resulting from the presence of antibodies to DUG virus. Antibodies to RVF virus were found in about 8% of adult cattle. Zebus do not play an important role in the spread of CHIK and WSL viruses among humans; these viruses were found in only one and 5, respectively, of the 183 cattle examined.

Keratitis, ichthyosis and deafness (KID) syndrome

Keratitis, ichthyosis, deafness (KID) syndrome is a genetically determined disorder. The present case is having marked photophobia, bilateral corneal ulceration with vascularisation, neurosensory deafness and skin changes.

Oligonucleotides as short as 7-mers can be used for PCR amplification

Amplification of DNA sequences using the polymerase chain reaction (PCR) requires as primers two oligonucleotides, which are carefully designed for length and G/C content. Such primers are generally between 18 and 30 bases long so that the primer sequences can amplify a unique sequence in the target genome; they should possess a minimal degree of secondary structure. We have tested the minimum length of G/C-rich and palindromic oligonucleotides to be used as primers in PCR. Oligonucleotides with sequences corresponding to the recognition sites of rare restriction enzymes were used on the DNA of vector constructs as model template DNA. Surprisingly, we found specific amplification with a low background over a wide range of temperatures for oligonucleotides as short as 7 nucleotides. This findings contradicts the previously reported empirical relationship between oligonucleotide length and ability to trigger amplification and points to the complex relationship between thermodynamic and kinetic criteria in relation to PCR. This technique should lead to new application in the cloning and screening of complex genomes.

Cell immunofluorescence and brain extract based dot-immunobinding assay in identification of arboviruses

Infected mouse brain homogenates were semi-purified and used in a dot-immunobinding assay to identify the corresponding arboviruses.

Neural network feature detector for real-time video signal processing

The application of artificial neural networks to real-time image processing tasks requires the use of dedicated, high performance hardware. A linear array processor called HANNIBAL has been developed which implements the backpropagation neural learning algorithm on-chip. This paper considers the design of a complete neural system which integrates HANNIBAL into an existing image processing environment. The goals for the design of the system have been set partly by the primary application, namely feature recognition, but mainly by the desire for a flexible, high performance hardware tool for the study and evaluation of range of neural image processing applications.

Reducing bacteria in dental aerosols: pre-procedural use of an antiseptic mouthrinse

This study, using a simulated office visit model, showed that the pre-procedural use of an antimicrobial mouthrinse produces a significant reduction in number of viable bacteria in a dental aerosol.

No effect of an antiaggregant treatment with aspirin in small cell lung cancer treated with CCAVP16 chemotherapy. Results from a randomized clinical trial of 303 patients. The "Petites Cellules" Group

BACKGROUND

Experimental, and more recently, clinical data have suggested the influence of hemostasis in the spread of malignant disease.

METHODS

To complete research in this type of coagulation and cancer, a multicentric randomized clinical trial was performed, including 303 patients with small cell lung cancer (SCLC), treated by the addition of aspirin at 1 g/day (a dosage at which aspirin is considered to be a platelet aggregation inhibitor) to combined chemotherapy.

RESULTS

Survival was not increased in the aspirin-treated group (P = 0.90). The analysis according to the extent of disease (limited or extensive disease) did not modify that conclusion.

CONCLUSIONS

This result does not confirm the hypothesis that, in SCLC, aspirin (a platelet aggregation inhibitor) reduces metastasis formation and local tumor thrombogenesis.

An improved clinical method for detecting meningeal irritation

Neck stiffness is the most important sign of meningitis. When the neck is flexed, the inflamed nerve roots and meninges of the cervical region get stretched. This causes protective muscle spasm manifesting as neck stiffness. Kernig's sign represents similar phenomena involving the distal spinal cord and related nerves. A manoeuvre that stretches the neural elements of the whole length of the spinal canal simultaneously will be a more sensitive test for meningeal irritation. Eliciting neck stiffness while the patient sits up with knees extended achieves this. This method is more sensitive, specific, and amenable to objective assessment.

Pharmacological tolerance to alpha 1-adrenergic receptor antagonism mediated by terazosin in humans

Chronic administration of alpha 1-receptor antagonists is associated with loss of clinical efficacy, especially in congestive heart failure, although the mechanism is uncertain. To evaluate changes in venous alpha 1-adrenoceptor responsiveness during chronic alpha 1-adrenoceptor blockade, dose-response curves to phenylephrine and angiotensin II were constructed in 10 healthy subjects before, during, and after administration of terazosin 1 mg orally for 28 d. Terazosin initially shifted the dose-response curve of phenylephrine to the right, with a significant increase in ED50 for phenylephrine from a control value of 102 to 759 ng/min on day 1 of terazosin (P < 0.001). However, by day 28, the dose-response curve had shifted back towards baseline with an ED50 of 112 ng/min. After discontinuing terazosin, the ED50 for phenylephrine remained near the baseline value, indicating no evidence of supersensitivity to phenylephrine. There was no change in responsiveness to angiotensin II during the course of treatment with terazosin. Plasma terazosin concentrations were stable throughout the period of drug administration. The mean Kd of terazosin was estimated as 11 +/- 15 nM in the first few days of treatment. This study demonstrates that pharmacological tolerance to the alpha 1-adrenoceptor blocking action of terazosin occurs in man and may be responsible for loss in efficacy with chronic therapy.

Desensitization of nitrate-induced venodilation: reversal with oral N-acetylcysteine in humans

The objective of this study was to determine whether the dorsal hand vein could be used as a model to study tolerance to oral nitrates, and whether oral N-acetylcysteine (NAC) could reverse tolerance if present. Dose-response curves to nitroglycerin were constructed for 11 normotensive volunteers before and during treatment with a sustained-release formulation of isosorbide dinitrate, 80 mg, three times daily for 7 days and followed by concurrent treatment with NAC at a mean dose of 150 mg/kg/day, in divided doses, for 2 days. In separate studies, dose-response curves were constructed for seven normotensive volunteers before and after treatment with oral NAC at the same dose for 2 days. Nitroglycerin's Emax was significantly attenuated from 115 +/- 36 to 77 +/- 22% after treatment with isosorbide dinitrate alone (p < 0.009). Concurrent treatment with NAC reversed this decrease, as nitroglycerin's Emax of 108 +/- 26% during coadministration of isosorbide dinitrate and NAC was not different from its Emax in the control period. There was also no difference in the dose of phenylephrine required to cause 80% of maximal venoconstriction throughout the study. These studies demonstrate that smooth muscle tolerance to nitrates can be demonstrated in medium-sized veins in humans. In addition, high-dose oral NAC can reverse existing tolerance to oral nitrates in human veins. These results indicate that the dorsal hand vein compliance technique is a good model for the clinical investigation of tolerance to nitrates in humans.