Trypsin-mediated semisynthesis of salmon calcitonin

Salmon calcitonin, CT(1-32)·NH₂, was synthesised by the trypsin-mediated coupling of the peptide fragments CT(1-24) and CT(25-32)·NH₂, prepared by conventional Fmoc solid-phase chemistry. Optimal conditions regarding reaction time course, pH, proportion of catalyst, substrate concentration and composition of the reaction medium were determined from initial studies on the coupling of CT(1-11) to CT(12-24) and of CT(12-24) to CT(25-32)·NH₂. For the final successful semisynthesis, we found that it was unnecessary to protect lysine residues not involved in the coupling, and that secondary hydrolysis at these sites could be prevented by increasing the pH of the reaction medium. The reaction achieved equilibrium after 30-45 min, with overall conversion of around 30% of the initial amount of CT(1-24) substrate into product. Yields were depressed due to cyclisation of the CT(1-24) substrate via air-oxidation of the Cys¹ and Cys⁷ residues.     

An evaluation of Gambusia affinis and Bacillus thuringiensis var. israelensis as mosquito control agents in California wild rice fields

The mosquito control potential of the mosquitofish and Bacillus thuringiensis var. israelensis (Bti) were evaluated in experimental wild rice fields in Lake County, California. Fields were assigned one of six treatment: control, 1.1 kg/ha G. affinis, 3.4 kg/ha G. affinis, Bti only (6 kg/ha Vectobac granules), 1.1 kg/ha G. affinis plus Bti and 3.4 kg/ha G. affinis plus Bti. Gambusia affinis, at both release rates, significantly reduced the mosquito population at densities exceeding 100 fish/minnow trap. Treatments with Bti significantly reduced larval population; however, the populations in the fields without fish rebounded to pretreatment levels within two weeks. In fields stocked with G. affinis and treated with Bti, populations remained low after Bti treatment. Nontarget populations of arthropods were significantly lower in fields stocked with G. affinis than in fields without fish on one or more sampling dates.     

Effect of oral and inhaled cetirizine in allergen induced bronchoconstriction

Cetirizine is a potent, selective H₁ histamine receptor antagonist. The effect of oral and inhaled eetirizine was assessed on the early bronchoconstrictor response to inhaled allergen in 10 mild atopie asthmatic patients in a double-blind, randomized, plaeebo controlled trial. All were sensitive to Dermatophagoides pleronyssinus and this was used as the provoking allergen. The geometric mean PD20 FEV] values obtained at allergen challenge were measured as cumulative breath units (c.b.u.) and following oral cetirizine, inhaled cetirizine and placebo were 124–5, 75–7 and 76–7 c.b.u. respectively. These did not differ significantly. We conclude that neither oral nor inhaled cetirizine significantly attenuates the early response to inhaled allergen in atopie asthmatic subjects. However, the method of repeated allergen challenge is likely to be relatively insensitive. Clinical and Experimental Allergy, [o]. 23, pp. 528–531.     

Distribution of normal and abnormal fluid collections in the glenohumeral joint: Implications for MR arthrography

Although magnetic resonance (MR) images of the glenohumeral joint frequently demonstrate intraarticular fluid, no specific criteria have, to the authors' knowledge, been published that allow accurate assessment of the amount of fluid present. Also, despite the increasing use of MR arthrography of the shoulder, the optimal amount of intra-articular fluid that should be used with this technique has not been determined. The authors progressively distended the glenohumeral joint in six cadaveric shoulder specimens with a dilute gadopentetate dimeglumine solution and obtained MR images after injection of 2, 5, 10, 15, and 20 mL of the solution. The pattern of fluid distribution was evaluated, and these results were then used to estimate the amount of fluid that was present in the glenohumeral joint on MR images of 20 shoulders obtained in 12 asymptomatic volunteers. In 14 of these shoulders, intraarticular fluid was present; however, in none was more than 2 mL evident. Results of the cadaveric study also indicated that 15 mL of intraarticular fluid appears to be the optimal amount for MR arthrography.     

Radiologische und histologische Beobachtungen an zentralen Talusfrakturen

In einer prospektiven Studie zentraler Talusfrakturen wurden radiologische Daten (Nativr?ntgenbild, CT, MRT) auf ihre Korrelation zum histologischen Befund (Biopsie zum Zeitpunkt der Schraubenentfernung) überprüft. Bei 9 Frakturen an 8 Patienten (Alter 14 – 48 Jahre) handelte es sich um Frakturen des Typs Hawkins I und II je einmal sowie des Typs III viermal; in 3 weiteren F?llen lagen K?rperfrakturen vor. Innerhalb von 24 h nach dem Unfall wurden 7 Frakturen verschraubt und 2 mit Bohrdr?hten adaptiert. Das verletzte Bein wurde für 14 – 53 Wochen post trauma vollst?ndig entlastet. Die Beobachtungszeit betrug mit einer Ausnahme 2 Jahre oder mehr; 4 Patienten zeigten am letzten R?ntgenbild einen intakten Talus, 4 Patienten zeigten partielle Einbrüche des Talusdoms und in 1 Fall war ein Teileinbruch fraglich. Die histologische Untersuchung (16 – 52 Wochen post trauma) zeigte in allen F?llen osteozytenfreien origin?ren Knochen mit Anlagerung neuen Knochens in individuell recht unterschiedlichem Ausma?. Das Hawkins-Zeichen war in 6 F?llen partiell positiv, sowie je einmal positiv und einmal negativ. Im CT konnte sowohl Dekalzifikation als auch Frakturheilung besser als im R?ntgenbild beobachtet werden. Das MRT-Signal war 5mal normal, 2mal partiell und einmal komplett pathologisch. Positives Hawkins-Zeichen und normales Signalverhalten sind prognostisch günstig zu werten. Es kam jedoch in Folge zentraler Talusfraktur auch bei radiologisch günstigem Verlauf zur Osteonekrose wenigstens von Teilen Talus gefolgt von schleichendem Ersatz. Die offenbar bei jeder zentralen Talusfraktur gest?rte Vaskularisation wurde von keinem radiologischen Befund einwandfrei reflektiert.      

The influence of anaesthetic techniques and type of delivery on peripartum serum interleukin-6 concentrations

Background: Interleukin-6 is a pleiotropic cytokine with a wide range of physiological activities. It plays an important role in the immuno-neuro-humoral axis during stress and surgery.
Methods: Serum interleukin-6 in parturients was measured on hospital admission, immediately after birth and 12 and 24 hours later. All parturients had uncomplicated pregnancies, and delivered vaginally without (n=31) or with (n=20) epidural analgesia, or underwent Caesarean section under epidural (n=20) or general (n=10) anaesthesia.
Results: Serum interleukin-6 assayed immediately following Caesarean section was low, but peaked 12 hours later, irrespective of the anaesthetic technique or other foetomaternal characteristics. Patients who delivered vaginally showed the highest interleukin-6 levels immediately after delivery. These were positively correlated with serum interleukin-6 on admission and duration of labour. Serum interleukin-6 was significantly higher in parturients who had epidural analgesia, and was significantly lower in those receiving intravaginal prostaglandins compared to those without prostaglandins.
Conclusion: The interleukin-6 response after Caesarean section can be explained by a generalized acute phase response to surgery, with no anaesthetic, maternal or neonatal interference. The rapid increase in peripartum serum interleukin-6 levels after vaginal delivery reflects, in part, cervical ripening or labour, their physiological triggers and psychological or physical stress. Regional anaesthesia, duration of labour and exogenous prostaglandin administration can modulate the peripartum interleukin-6 response and subsequently the physiological effects of this cytokine.     

Age and gender interactions on verbal memory performance.

Age and gender effects on verbal episodic memory are well established. However, the possibility of interactions between age and gender has been raised by studies linking estrogen and verbal memory performance, and by research suggesting gender differences in age-related cortical atrophy. We evaluated whether age by gender interactions in verbal memory were present. Subjects within three years of the median age of menopause were excluded from a large cohort of normal subjects, resulting in a younger sample (16-47 years) of 288 men and 285 women, and an older sample (55-89 years) of 201 men and 245 women. All subjects were administered the CVLT-2, a multiple-trial list-learning task. Verbal memory was negatively correlated with age for younger men, older men, and older women, but not for younger women. Multivariate analyses indicated age by gender interactions on memory for the younger group but not the older group. Results indicate that verbal memory declines with age for younger men but not younger women, whereas both older men and older women show age-related declines. These findings are consistent with hypotheses linking estrogen and verbal memory performance, and with imaging data suggesting that age-related hippocampal atrophy is found in younger men but not younger women. The role of estrogen on cognition in normal aging warrants further study.     

Comparison in the immunological properties of Borrelia burgdorferi isolates from Ixodes ricinus derived from three endemic areas in Switzerland.

Borrelia burgdorferi isolates were obtained from Ixodes ricinus from three sites in Switzerland. They were examined by SDS-PAGE and immunoblotting. The phenotypes, in respect of three outer surface proteins (Osp), differed between the sites of collection. In site 1, most isolates had an OspA of 31 kDa and an OspB of 34 kDa; in site 2, isolates presenting an OspA of 33 kDa dominated and in site 3, the isolates with an OspA of 32 kDa and an OspB of 35 kDa were most frequent. This distribution differed significantly. About half of the isolates from sites 1 and 3 reacted with anti-OspA monoclonal antibody H5332 compared to 29% from site 2. Site 1 isolates reacted significantly more frequently (81%) with another anti-OspA monoclonal antibody LA-31 than isolates from site 3 (P < 0.0001). These findings have implications for the epidemiology of Lyme borreliosis, for the further development of serodiagnostic reagents and for the development of a vaccine.     

Mothers' and children's intakes of vitamin A in rural Bangladesh.

The vitamin A intake of 370 mothers and 183 children 3-27 mo of age in rural Bangladesh was ascertained monthly from January to July in 1986. For mothers, dark green leafy vegetables and fruits were the main sources of vitamin A. Vitamin A from vegetables, the single most important source, did not show consistent associations with wealth or with the other socioeconomic indicators. In May and June, fruits provided wealthier (and more educated) mothers with significantly higher vitamin A intakes than poor mothers, whereas in January the poorer mothers had higher intakes. When breast milk was included, average intakes for children came close to 100% of the recommended dietary allowance; the only other significant source of vitamin A for children was seasonally available mangoes. Fourteen children who had stopped breast-feeding by the end of the study were at very high risk of vitamin A deficiency when fruits were not plentiful.     

Progressive multifocal leukoencephalopathy in a lung transplant recipient.

Progressive multifocal leukoencephalopathy (PML) is a sub-acute, demyelinating disease of the brain caused by a human polyomavirus. We describe a patient with the onset of PML 7 months after lung transplantation. The patient was treated with immunosuppressive modulation and cidofovir, a new anti-viral therapy for PML, with stabilization of the symptoms. We also review the 4 additional reports in the literature of PML after heart and lung transplantation. Progressive multifocal leukoencephalopathy may become more prevalent as the population of heart and lung transplantation recipients increases.