Malaria chemoprophylaxis among European tourists in tropical Africa: use, adverse reactions, and efficacy

In order to determine knowledge, attitudes and practices towards malaria prophylaxis, as well as its side-effects and efficacy, a self-administered questionnaire was distributed to European travellers on return flights from tropical Africa to Europe. Between 1985 and 1988 the questionnaire was completed by 44,472 passengers (80.1% of those on board) on 242 flights. A follow-up questionnaire was completed by 42,202 (94.9%) of the same travellers 3 months later. Almost all knew about the risk of malaria, but 10% relied solely on advice from nonmedical sources. While 55.6% had taken at least one measure against mosquito bites, only 4.5% adopted three such measures (used repellents and insecticides and wore long clothing after dusk). Compliance with chemoprophylaxis use was reported by 57.0% of travellers who spent less than 3 months in Africa, compared with 29.2% who stayed 3-12 months. Depending on the antimalaria regimen taken, 11-44% of the travellers experienced adverse effects, while four deaths were attributed to the chemoprophylaxis. The incidence of malaria per month of exposure for travellers who took no chemoprophylaxis was 15.2 per 1000 in East Africa and 24.2 per 1000 in West Africa. In East Africa, the prophylactic efficacy of the currently recommended antimalaria regimens (relative to that of no chemoprophylaxis) was zero for a chloroquine dosage of 300 mg base per week (4 malaria fatalities), 64.1% for a chloroquine dosage of 600 mg base per week (P = 0.03), and 94.0% for mefloquine (P = 0.003).

Cardiac pacemaker inhibition by transcutaneous electrical nerve stimulation

The use of transcutaneous electrical nerve stimulation (TENS) has increased in recent years for the management of chronic pain. One of its few contraindications is the presence of a cardiac pacemaker. Clinicians have recommended that cardiac monitoring be performed for a short interrupted period during the first application of TENS to ensure safety. We present two patients who were given trials of TENS for different chronic pain complaints. In both cases, electrocardiograms during the TENS trial did not reveal cardiac pacemaker dysfunction, but extended cardiac monitoring with the Holter monitor showed interference with pacemaker function. The abnormalities did not recur after reprogramming the sensitivity of the pacemakers. We suggest the use of extended cardiac monitoring for patients with cardiac pacemakers during the prolonged use of TENS to ensure safety and to determine any need for reprogramming of the pacemakers. Patients with cardiac pacemakers should not be excluded from the use of TENS, but careful evaluation and extended cardiac monitoring should be performed.

Amphiphilic networks: II. Biocompatibility and controlled drug release of poly[isobutylene-co-2-(dimethylamino)ethyl methacrylate]

Biocompatibility and diffusional characteristics of recently synthesized unique amphiphilic networks, i.e., copolymers of methacryloyl-capped polyisobutylene (MA-PIB-MA) with 2-(dimethylamino)-ethyl methacrylate (DMAEMA) have been examined. Excellent biocompatibility and biostability were obtained after 7 weeks with films containing 53-58% MA-PIB-MA implanted dorsally or abdominally in rats. In contrast, networks with higher or lower MA-PIB-MA contents showed decreased biocompatibility. These amphiphilic networks were also studied as potential implantable drug release systems. Bromophenol blue and folic acid were used as model compounds for drug release. Diffusion of these chemicals from loaded networks into water showed a marked pH dependence. Under specific well-defined conditions (MA-PIB-MA/DMAEMA content, pH, time range) release was observed to be independent of time (zero-order release).

Analysis of reassortment and superinfection during mixed infection of Vero cells with bluetongue virus serotypes 10 and 17

The reassortment of genome segments during mixed infection of Vero cells with bluetongue virus (BTV) serotypes 10 and 17 was investigated, using non-selective conditions for analysis of the progeny of mixed infections. Reassortment was found to be an early event in the BTV replication cycle, indicating that progeny BTV genomes undergo a single round of reassortment. Non-random segregation of individual genome segments was observed in crosses at equal multiplicity of infection, and was confirmed in crosses performed at unequal multiplicity. Asynchronous infections showed that superinfection exclusion resulted in the failure of the superinfecting virus to contribute genome segments to reassortants if the second virus followed the first by more than 4 h. The significance of these results for the evolution and epidemiology of BTV is discussed.

From playgroup to preschool: facilitating early integration experiences

This paper discusses community playgroup and preschool settings for non-disabled children as programme options for infants and preschoolers with a variety of physical and mental impairments. These options provide age-appropriate integration experiences which may result in benefits to parent and child, realistic developmental expectations, and a cultural expectation that social integration is a basic part of any child's education. The discussion identifies advantages to beginning integration before the age of 5 years and emphasizes the need for individualized services, ongoing staff training, support for parents, and programme evaluation.

Atheromatous embolism: varied clinical presentation and prognosis

Microemboli composed of atheromatous debris can produce sudden failure of one or many organ systems. The soft tissues of the lower extremity are almost always involved, and may sustain the only significant injury. Atheromatous embolization occurs more commonly than is recognized, and its incidence may be increasing. We report ten cases that demonstrate the variability in presentation and prognosis. These data and a review of the existing literature suggest an extremely grave prognosis in patients with generalized organ system involvement, as opposed to those patients with involvement of the lower extremity only. Treatment consists of general supportive care. Anticoagulation or lytic therapy appears to be of no benefit, and may actually contribute to embolization. We discuss new pharmacologic agents as possible treatment for the intense local ischemia, and recommend selective use of lumbar sympathectomy in cases of impending loss of lower extremity tissue.

The parascapular flap for treatment of lower extremity disorders

The parascapular flap was used as a free microvascular transfer for soft-tissue resurfacing of 11 lower extremities. The diagnoses included four cases of osteomyelitis, three cases of vascular ulceration, one case of combined osteomyelitis and vascular ulceration, two cases of posttraumatic heel defects, and one case of extensive soft-tissue contracture overlying a posttraumatic defect of the femur. All cases were successful clinically. Anatomically, the parascapular flap is supplied by the cutaneous parascapular artery, a branch of the circumflex scapular artery, which itself derives from the subscapular artery. Flap territory may reach 15 x 30 cm, and the vascular pedicle can extend 14 cm if the subscapular artery is taken. Advantages of this flap include the constancy, length, and caliber of the vascular pedicle; the length and width attributes, which allow both coverage of large wounds and primary closure of the donor defect; and an absence of disruption of musculoskeletal function.

Phenotypes of rotavirus reassortants depend upon the recipient genetic background

We have previously characterized the biological and immunological properties of a simian rotavirus SA11 variant (4F) with an altered genome segment 4. The SA11-4F variant formed large plaques in the presence of protease, formed small clear plaques in the absence of protease, and grew to high titer in the presence of protease when compared to our standard wild type (SA11 clone 3). To determine the genome segment of the rotavirus SA11 variant 4F that encoded the unique protease-associated phenotypes of the variant, reassortants were generated that segregated the outer capsid genes of 4F onto a genetic background derived from either the bovine rotavirus B223 or our standard SA11 wild type (clone 3), both of which have contrasting protease-associated phenotypes. The parental and reassortant viruses were examined to determine which genes from the 4F variant encoded the ability (i) to form large plaques in the presence of protease, (ii) to form small clear plaques in the absence of exogenous protease, and (iii) to grow to significantly higher titer in the presence of protease. These phenotypes could be transferred to a clone 3 genetic background by a single genome segment from the 4F variant segment 4. However, in the 4F/B223 reassortants a different and unexpected situation was found. On a B223 genetic background the same phenotypes segregated with a combination of a minimum of two 4F genome segments, segments 4 and 9. These results indicate that the recipient genetic background onto which the genes of a donor rotavirus are reassorted can affect the phenotypes conferred by the presence of the donor segments. Thus, the results of segregation mapping experiments using reassortant viruses should be interpreted with caution.

Biological and immunological characterization of a simian rotavirus SA11 variant with an altered genome segment 4

We have studied a variant virus isolated from a stock of SA11 virus (H. G. Pereira, R. S. Azeredo, A. M. Fialho, and M. N. P. Vidal, 1984, J. Gen. Virol. 65, 815-818). This virus, designated 4F, was initially identified by its faster electrophoretic mobility for genome segment 4. The variant was analyzed to determine if the altered electrophoretic mobility of genome segment 4 could be correlated with phenotypic changes. Comparison of our standard laboratory SA11 virus (clone 3) with the 4F variant showed the following: (i) The 4F variant possesses a viral hemagglutinin (VP4) with a higher apparent molecular weight than clone 3. (ii) The 4F variant produces large plaques when assayed in vitro, as compared to clone 3. (iii) The 4F variant produces plaques in the absence of proteolytic enzymes, whereas clone 3 does not. (iv) The 4F variant reacts with serotype-specific neutralizing monoclonal antibodies to VP7, but fails to react with several neutralizing anti-VP4 monoclonal antibodies generated to SA11 clone 3. (v) The 4F variant grows to a higher titer and is more stable than clone 3. (vi) The 4F variant produces a VP4 that appears to be more susceptible to cleavage by trypsin than is the VP4 of clone 3. Further analyses with the 4F variant may lead to an understanding of the molecular basis for these altered phenotypes that appear to be related, at least in part, to the product of genome segment 4.

A phase 1a clinical trial of LYM-1 monoclonal antibody serotherapy in patients with refractory B cell malignancies

Ten patients with refractory B cell lymphomas were treated with weekly intravenous infusions of escalating doses of murine monoclonal antibody (MoAb) LYM-1 over four weeks. LYM-1 is a recently developed IgG2a murine MoAb that recognizes a polymorphic HLA-Dr antigen on surfaces of normal and malignant B cells but does not bind to any other normal tissues. MoAb LYM-1 has several advantages for serotherapy, since the antigen it recognizes is not shed from the cell surface and does not modulate in response to MoAb therapy. Furthermore, in vitro studies have indicated significant anti-tumour activity against lymphoma cell lines. In the current trial, dose-dependent levels of free LYM-1 were detected in the serum of all patients, but penetration of extravascular tumour tissues was poor. No significant toxicity or human anti-mouse antibody responses were observed in any patient. Clinical responses were minor and appeared to correlate with the number of infiltrating T cells seen in the initial lymphoma specimens. LYM-1 appears to be well-tolerated and has demonstrated several potential advantages as a therapeutic agent in patients with lymphoma. The mechanism of anti-tumour effect and plans for further clinical studies are discussed.

Respiratory criteria of fitness for surgery and anaesthesia

A retrospective analysis has been undertaken of 53 operations in 42 patients with severe chronic obstructive airway disease. All patients had a forced expiratory volume in 1 second between 0.3 and 1 litre, but the outcome of surgery was successful after their first operations, all of which were elective; 38 of the 42 had uneventful anaesthesia and surgery together with a normal postoperative period, while four had artificial ventilation of the lungs. The best predictors of the use of postoperative ventilation were the arterial PO2 and whether the patient was dyspnoeic at rest.

Molecular properties of p-(dimethylamino)benzaldehyde bound to liver alcohol dehydrogenase: a Raman spectroscopic study

We have studied the binding nature of an aromatic aldehyde to the catalytic site of liver alcohol dehydrogenase from horse (LADH) using preresonance Raman spectroscopy. The compound p-(dimethylamino)benzaldehyde (DABA) is converted to the corresponding alcohol in the presence of nicotinamide adenine dinucleotide (NADH) and a catalytic amount of enzyme at neutral pH. A stable ternary complex of LADH/NADH/DABA can be formed if enzyme and coenzyme are in excess at high pH [Jagodzinski, P. W., Funk, G. F., & Peticolas, W. L. (1982) Biochemistry 21, 2193-2202]. We have obtained the preresonance Raman spectrum of bound DABA by subtracting the contribution of the binary complex of LADH/NADH from the spectrum of this stable ternary complex. In order to understand the normal mode patterns of DABA, four isotopically labeled DABA derivatives were synthesized and their Raman spectra, in solution and in the ternary complex, were measured. Three of these compounds contain substitutions in the functionally important aldehyde moiety: (i) In one such substitution, the aldehydic hydrogen atom was replaced by a deuterium; (ii) in another, this hydrogen atom was replaced by deuterium, and the aldehydic carbon atom was replaced by 13C; and (iii) in the third derivative, only the carbon atom was replaced by 13C. The fourth derivative has had the two hydrogen atoms at the 3- and 5-positions of the DABA ring replaced by deuterium atoms. We find that many of the spectral modes are fairly extended, involving both stretching and bending motions of the entire molecule, although a few modes are quite localized. We find that the normal mode structure of DABA changes considerably when it binds to LADH/NADH. As a model for the bound DABA, we have examined the zinc complexes of DABA (and all four isotopically labeled samples) in anhydrous diethyl ether and methylene chloride. A striking correspondence between the Raman spectra of the enzyme-bound DABA and DABA-Zn complexes in solution is found, which extends to all the isotopically labeled derivatives. This suggests that one of the major roles of LADH in the binding of DABA is to provide a divalent zinc ion to form a first-sphere Lewis acid complex. The data also suggest other interactions between enzyme-bound DABA with its protein surroundings and with the coenzyme NADH are quite minor. An estimate of the carbonyl bond character of bound DABA had been made on the basis of the response of Raman bands to isotopic labeling and on trends observed in spectra of DABA in solvents of various polarities.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibition of the metabolism of urethane by ethanol

Ethanol has been shown to inhibit the localization of [ethyl-1-14C] urethane in the male mouse, but the effect of ethanol on the metabolism of urethane has not been clarified. Consequently, the concentration of unchanged urethane was determined in the blood of male mice up to 11 hr after oral administration of urethane with or without ethanol. A high and constant blood level of urethane persisted for 8 hr after the administration of an ethanolic solution of [ethyl-1-14C] urethane (125 mumol/kg, 10 muCi/20 g of mouse, 5 g of ethanol per kg, po); the blood level of ethanol was at or above 150 mg/dl during these 8 hr. In contrast, rapid clearance of radioactivity was observed in mice treated with [ethyl-1-14C]urethane dissolved in water. Coadministration of ethanol with urethane decreased the rate of 14CO2 expiration; furthermore, covalent binding with liver protein was delayed about 8 hr and was less than that in the group treated with urethane in water. The metabolism of urethane and production of 14CO2 from [carbonyl-14C]urethane by mouse liver homogenate in vitro were inhibited by the presence of ethanol (greater than 10 mM); these concentrations of ethanol in vitro are about the same as those that are inhibitory in vivo, but the extent of inhibition suggests that the liver is not the only site of metabolism of urethane. These results indicate that ethanol can inhibit the initial metabolism of urethane, prevent the formation of active metabolites, and allow urethane to persist in blood.

Auditory space representation in the inferior colliculus of the FM bat, Eptesicus fuscus

The auditory spatial response areas of 333 inferior collicular (IC) neurons of Eptesicus fuscus were studied under free-field acoustic stimulus conditions. A stimulus was delivered from a loudspeaker placed 14 cm in front of a bat and the best frequency of an encountered neuron was determined. Then a best frequency (BF) stimulus was delivered as the loudspeaker was moved across the frontal auditory space to determine the response center of the neuron. At the response center, the neuron had the lowest minimum threshold. The stimulus was then raised 3-15 dB above the lowest minimum threshold of the neuron and the spatial response area for each stimulus intensity was measured. The response center and spatial response area of a neuron measured with a one-octave downward-sweep FM stimulus were similar to those measured with the pure tone pulse. The spatial response area of a neuron expanded asymmetrically with the stimulus intensity. High BF neurons generally had smaller spatial response areas than low BF neurons had. All 333 response centers were located in the contralateral auditory space. Response centers of low BF neurons tended to be located laterally while those of high BF neurons were located medially. Although each neuron had a point of lowest minimum threshold in the contralateral auditory space, the point-to-point representation of the auditory space was not systematically organized. This representation was not correlated with the recording sites of the neurons in the mediolateral, posteroanterior and dorsoventral axes of the IC.

Recombinational repair of hydrogen peroxide-induced damages in DNA of phage T4

Recently, hydrogen peroxide and its free-radical product, the hydroxyl radical (OH.) have been identified as major sources of DNA damage in living organisms. They occur as ubiquitous metabolic by-products and, in humans, cause several thousand damages in a cell's DNA per day. They are thought to be a major source of DNA damage leading to aging and cancer in multicellular organisms. This raises two questions. First, what pathways are used in repair of DNA damages caused by H2O2 and OH.? Second, a new theory has been proposed that sexual reproduction (sex) evolved to promote repair of DNA in the germ line of organisms. If this theory is correct, then the type of repair specifically available during the sexual process should be able to deal with important natural lesions such as those produced by H2O2 and OH. . Does this occur? We examined repair of hydrogen peroxide damage to DNA, using a standard bacteriophage T4 test system in which sexual reproduction is either permitted or not permitted. Post-replication recombinational repair and denV-dependent excision repair are not dependent on sex. Both of these processes had little or no effect on lethal H2O2 damage. Also, an enzyme important in repair of H2O2-induced DNA damage in the E. coli host cells, exonuclease III, was not utilized in repair of lethal H2O2 damage to the phage. However, multiplicity reactivation, a recombinational form of repair depending on the sexual interaction of two or more of the bacteriophage, was found to repair lethal H2O2 damages efficiently. Our results lend support to the repair hypothesis of sex. Also the homology-dependent recombinational repair utilized in the phage sexual process may be analogous to the homology-dependent recombination which is widespread in diploid eucaryotes. The recombinational repair pathway found in phage T4 may thus be a widely applicable model for repair of the ubiquitous DNA damage caused by endogenous oxidative reactions.