The structure of the human microsporidium found by Yachnis and colleagues in two AIDS patients (Am. J. Clin. Pathol. 106: 535-43, 1996) (hereafter referred to as HMY) was investigated by light and transmission electron microscopy and compared with Thelohania apodemi Doby, Jeannes et Raoult, 1963, a microsporidian of small rodents. The fine structure of the HMY was found to be similar to that of Trachipleistophora hominis Hollister, Canning, Weidner, Field, Kench et Marriott, 1996. Characteristic is the presence of a thick layer of electron dense material on the outer lace of the meront plasmalemma, which is maintained during the whole life cycle and which later persists as an electron dense coat on the sporophorous vesicle (SPOV). However, HMY is distinguished from T. hominis during sporogony, as two types of SPOV and spores are formed in HMY. One type of SPOV contains thick-wallcd spores (usually 8 or more in number) with anisofilar polar filaments of 7 + 2 pattem, while the other type contains only two thin-walled spores with a smaller number (3-5) of isofilar polar filament coils. The HMY differs from T. apodemi which also forms SPOV with 8 spores inside, but the spores of which are larger in size and have 9 + 2 polar filament pattern.
Two pairs of wire electrodes were used to record afferent and efferent single fibre extracellular action potentials (APs) from human nerve root filaments. The nerve fibres were identified according to the group to which they belong by comparing the afferent and efferent conduction velocity distribution histograms and identifying peaks and ranges of nerve fibre groups. Secondary muscle spindle afferents and a2-motoneurones (FR) were identified by having the same peak group conduction velocity (calibration relation), which is 50 m/s at 36 °C. On the basis of AP wave form comparisons, the natural impulse patterns of five secondary muscle spindle afferents, two fusimotor motoneurones and two oscillatory firing a2-motoneurones could be identified in the dorsal S4 root. The patterns of single endings of secondary spindle afferent fibres could be identified. The shortest interspike intervals of single endings of all secondary muscle spindle afferents had the same duration as the shortest interspike intervals of the two fusimotor fibres (80 ms) and equalled a half of the oscillation period of one repetitively firing a2-motoneurone (6 Hz) probably innervating the external anal sphincter (three AP impulse train firing). In another more rostral dorsal root filament (probably S3 or S2) of the same human, the interspike intervals of six secondary spindle afferents were more variable. The values of peaks in the interspike interval distributions ranged from 60 to 102 ms. In the coccygeal root, the interspike interval duration ranged from 160 to 185 ms, directly contributing to the drive of the oscillatory firing a2-motoneurone. The different agreement between the oscillation period and the interspike intervals of the spindle afferents in different segments indicate that the oscillatory firing CMS circuitry was localized within S3 to S5 segments of the conus medullaris for the drive of the anal sphincter. An a2-motoneurone firing repeatedly with 1 to 2 AP impulse trains, innervating most likely the external urethral sphincter, fired at a frequency of 9.1 to 6.7 Hz, a similar frequency of the oscillation as the interspike intervals from two activated stretch receptors of the urinary bladder wall. The measurements of this brain-dead human indicates that in this case the neuroneal circuitry driving the external anal sphincter was mainly confined to the sacral micturition and defecation centre, mainly located in the S3 to S5 segments.
To investigate the transmission of species of Cryptosporidium Tyzzer, 1907 in Timis County, Romania, 48 isolates of Cryptosporidium coccidia from 11 children, 29 calves and eight pigs were characterised by molecular analysis of two loci (SSU rRNA and 60-kDa glycoprotein gene). Overall, 22 isolates were amplified and sequence analyses revealed that all isolates were Cryptosporidium parvum Tyzzer, 1912. Two subtype families were identified, IIa and IId. Subtype IIdA22G1 (n = 4) was the single C. parvum subtype found in children. Subtypes found in calves included IIdA27G1 (n = 8), a novel subtype, IIdA25G1 (n = 5), IIdA22G1 (n = 2), IIdA21G1a (n = 1), and IIaA16G1R1 (n = 1). Subtype IIdA26G1 was found in a pig. These results were significantly different from previous Romanian reports, as the five subtypes of family IId identified in this study were never identified previously in this country. Thus, cattle may be a source of Cryptosporidium infections for humans and the transmission dynamics of C. parvum in Romania is more complex than previously believed., Patrícia Manuela Vieira, Narcisa Mederle, Maria Luísa Lobo, Kálmán Imre, Ovidiu Mederle, Lihua Xiao, Gheorghe Darabus, Olga Matos., and Obsahuje bibliografii
This study was designed to evaluate the extent of foot deformation in healthy subjects during standing on an immobile support and during slow tilts of the support platform by 1 deg. The angle in ankle joint was evaluated by two methods: as an angle of shin inclination relative to the platform and as an angle, calculated on the basis of recording of the projective length of the soleus muscle. It was shown that the real changes of the angle in ankle joint during standing on an immobile platform were up to 2 times smaller than the changes of angular position of the shin relative to vertical axis. However, considerable intersubject variability was observed in this respect. During slow tilts of the support platform a marked divergence was observed in the shape of recordings of two "ankle angles" in subjects with high foot compliance. The vertical displacements of the calcaneus recorded by means of a clamp rigidly fixed at the heel were 0.5±0.3 mm (the range 0.1 - 1 mm) for each degree of body deviation in the forward or backward direction. In 12 subjects, the average foot compliance was
0.04 ±0.03 deg/Mm (maximal value 0.1 deg/Mm). It can be assumed that the mechanical properties of the foot can appreciably influence the afferent outflow during maintenance of orthograde posture in man.