Dual fortification of salt with iron and iodine in women and children in rural Ghana.

OBJECTIVE: To test the efficacy of double-fortified salt (DFS) on the anaemia and iodine deficiency (ID) status of women and their children. DESIGN: Double-blind randomised controlled trial. SETTING: Sekyere West District of Ghana. SUBJECTS: In this eight-month trial, mildly anaemic or non-anaemic, non-pregnant, non-lactating women were randomised into three groups receiving: DFS plus weekly placebo (n = 61); iodised salt plus weekly 70 mg iron supplement (n = 65); or iodised salt (IS) plus weekly placebo (control group, n = 58). Correspondingly, their mildly anaemic and non-anaemic children aged 1-5 years were randomised into two groups receiving either the DFS (n = 23) or IS alone (control group, n = 59). RESULTS: At the end of the intervention, prevalence of anaemia in women remained unchanged in the DFS or IS plus weekly iron supplement group, but significantly increased by 19.5% in the control group (P = 0.039). In children, prevalence of anaemia in the DFS group significantly decreased by 21.7% (P = 0.025) while no change was observed in the control group. ID decreased significantly in all groups of women (P < 0.001) and children (P < 0.05), with no difference among groups of women and children. CONCLUSION: While the use of DFS prevented anaemia in women, it had a significant role in both the prevention and treatment of anaemia in children. Both the DFS and IS significantly reduced ID in women and children to a similar degree.

Complementation analysis of the Dichelobacter nodosus fimN, fimO, and fimP genes in Pseudomonas aeruginosa and transcriptional analysis of the fimNOP gene region.

The causative agent of ovine footrot, the gram-negative anaerobe Dichelobacter nodosus, produces polar type IV fimbriae, which are the major protective antigens. The D. nodosus genes fimN, fimO, and fimP are homologs of the Pseudomonas aeruginosa fimbrial assembly genes, pilB, pilC, and pilD, respectively. Both the pilD and fimP genes encode prepilin peptidases that are responsible for cleavage of the leader sequence from the immature fimbrial subunit. To investigate the functional similarity of the fimbrial biogenesis systems from these organisms, the D. nodosus genes were introduced into P. aeruginosa strains carrying mutations in the homologous genes. Analysis of the resultant derivatives showed that the fimP gene complemented a pilD mutant of P. aeruginosa for both fimbrial assembly and protein secretion. However, the fimN and fimO genes did not complement pilB or pilC mutants, respectively. These results suggest that although the PilD prepilin peptidase can be functionally replaced by the heterologous FimP protein, the function of the PilB and PilC proteins may require binding or catalytic domains specific for the P. aeruginosa fimbrial assembly system. The transcriptional organization and regulation of the fimNOP gene region were also examined. The results of reverse transcriptase PCR and primer extension analysis suggested that these genes form an operon transcribed from two sigma70-type promoters located upstream of ORFM, an open reading frame proximal to fimN. Transcription of the D. nodosus fimbrial subunit was found to increase in cells grown on solid media, and it was postulated that this regulatory effect may be of significance in the infected footrot lesion.

Virulence regions and virulence factors of the ovine footrot pathogen, Dichelobacter nodosus.

Ovine footrot is a debilitating and highly infectious disease that is primarily caused by the Gram-negative, anaerobic bacterium Dichelobacter nodosus. The major antigens implicated in virulence are the type IV fimbriae and extracellular proteases. The fimbriae show sequence and structural similarity to other type IV fimbriae, this similarity extends to genes that are involved in fimbrial biogenesis. Several acidic and basic extracellular serine proteases are produced by both virulent and benign isolates of D. nodosus. Subtle functional differences in these proteases appear to be important in virulence. In addition, there are two chromosomal regions that have a genotypic association with virulence. The partially duplicated and rearranged vap regions appear to have arisen from the insertion of a plasmid into a tRNA gene via an integrase-mediated site-specific insertion event. The 27 kb vrl region has several genes often found on bacteriophages and has inserted into an ssrA gene that may have a regulatory role in the cell. The determination of the precise role that each of these genes and gene regions has in virulence awaits the development of methods for the genetic analysis and manipulation of D. nodosus.

The surgical treatment of small deep intracranial ateriovenous malformations: a report of 85 cases.

A series of 85 patients having what are defined as small, deep intracranial arteriovenous malformations (AVMs) is analysed in terms of presentation, investigation, treatment and outcome. This group of patients is taken from a consecutive series of 306 patients with AVM treated over a 20 year period. The anatomical distribution was as follows: cerebral hemisphere 54 patients, basal ganglia and thalamus 6 patients, brain stem and cerebellum 19 patients and deep dural 6 patients. Haemorrhage, both subarachnoid and intraparenchymal, was the predominant mode of presentation (71 of 85 cases). Other presentations were with epilepsy (5 cases), headache only (4 cases), progressive focal deficit (1 case) and mixed (4 cases). The vast majority of patients (71 of 85, 83.5%) were treated surgically: 67 by surgery only, 3 by surgery following partial embolisation and one with focussed irradiation after subtotal excision. The overall outcome in this group at 1 month was 27 (38.0%) improved (largely due to haematoma removal), 42 (59.2%) unchanged and 2 (2.8%) worse. One of the unchanged group died during the second month with pulmonary complications following prolonged impairment of consciousness. The two patients worse at 1 month (Gd I -> Gd II) returned to Gd I within 3 months. There were 3 patients treated non-surgically (2 by focussed irradiation and 1 by embolisation) while 11 patients were not treated because they declined treatment (3 cases), they died before treatment could be carried out (3 cases), or treatment was deemed inadvisable (5 cases). The results of surgical treatment in small deep AVMs are compared with those of other treatment modalities, in particular focussed irradiation. It is argued on the basis of these figures that surgery remains the best treatment for these lesions.

Ocular motor dysfunction in HIV-1-infected subjects: a quantitative oculographic analysis.

We recorded eye and head movements in 13 human immunodeficiency virus type-1 (HIV-1)-infected patients with CD4 counts of less than or equal to 500 cells/mm3 using magnetic search coil oculography. Horizontal and vertical saccades, smooth pursuit, and vestibular smooth eye movements were recorded, as were horizontal antisaccades and vestibular memory-guided saccades. Rightward and leftward and upward and downward responses were analyzed separately. Compared to normal control subjects, HIV-1--infected patients performed the antisaccade test poorly, making the initial antisaccade in the correct direction (away from the target) in only 33% of trials. The mean final gaze position achieved during the vestibular memory-guided saccade task was less accurate for HIV-1-infected patients than for control subjects, and this correlated with inaccuracies on the antisaccade task. Horizontal saccades, horizontal and vertical smooth pursuit, and vestibular smooth eye movements were quantitatively normal. However, smooth pursuit showed directional asymmetries, vertically more than horizontally; horizontal and vertical unpredictable saccades were more inaccurate than predictable saccades; and vertical saccade latencies were prolonged. In patients with HIV-1 infection, abnormalities in vertical eye movements and relative asymmetries in smooth pursuit gains, both horizontally and vertically, are more sensitive and consistent indicators of CNS dysfunction than are horizontal eye movement abnormalities or measurements of absolute smooth pursuit gain and phase.

Identification of fimbrial assembly genes from Dichelobacter nodosus: evidence that fimP encodes the type-IV prepilin peptidase.

Dichelobacter nodosus (Dn) is the causative agent of footrot, an economically significant disease of sheep. One of the factors believed to be involved in the virulence of this organism is its ability to produce type-IV fimbriae, which are the major protective antigens. To investigate the process of fimbrial biogenesis in Dn, gene probes were constructed from pilus biogenesis genes of Pseudomonas aeruginosa (Pa) and used to isolate homologues from Dn. A homologue, designated fimP, of the Pa prepilin peptidase-encoding gene, pilD, was cloned using this approach. The fimP gene product was shown to possess endopeptidase activity when produced in Escherichia coli. Two other fimbrial biogenesis genes fimN and fimO, whose products show similarity to the Pa PilB and PilC proteins, respectively, were identified because of their linkage to fimP. The arrangement of fimN, fimO and fimP in Dn closely resembles the arrangement of pilB, pilC and pilD in Pa.

Characterization of a conjugative staphylococcal mupirocin resistance plasmid.

We studied conjugative plasmids encoding high-level mupirocin resistance. These plasmids were found in Staphylococcus aureus isolates from two geographic locations in the United States. Transfer genes on three mupirocin resistance plasmids with different restriction endonuclease profiles were indistinguishable by DNA hybridization from those on pG01, a conjugative aminoglycoside resistance plasmid representative of similar plasmids that are prevalent in the United States. One mupirocin resistance plasmid, pG0400 (34 kb), was smaller than pG01 (52 kb) because of the absence from pG0400 of DNA, found on pG01, that contained genes encoding resistance to aminoglycosides, trimethoprim, and quaternary ammonium compounds flanked by directly repeated copies of the insertion sequence (IS)-like element IS431-IS257. The plasmids pG0400 and pG01 were otherwise indistinguishable except for the presence in pG0400 of a 4.5-kb HinDIII fragment encoding mupirocin resistance. The added mupirocin resistance gene was flanked by two directly repeated copies of IS431/257. The nucleotide sequence of DNA contiguous to the outside of the IS elements, as well as those of the elements themselves, was identical in both pG01 and pG0400, and there were no target site duplications flanking either copy of the element. We conclude that the mupirocin resistance gene was added to an existing conjugative plasmid in conjunction with the deletion of other resistance genes by recombination at IS elements. The construction of conjugative plasmids carrying a mupirocin resistance gene may be a model for the mobility of other resistance genes newly acquired by staphylococci.

Transcriptional regulation by TrsN of conjugative transfer genes on staphylococcal plasmid pGO1.

The major conjugative transfer gene cluster of staphylococcal plasmid pGO1 (trs) consists of 13 open reading frames (trsA to trsM) transcribed from one DNA strand and a single 189-bp open reading frame (trsN) within the first 348 bp of trs that is transcribed divergently. Promoter regions for trsN and trsA partially overlap. TrsN, a 7,181-Da protein, was purified as a fusion to glutathione S-transferase and found to have DNA-binding activity. Increasing concentrations of the fusion protein progressively retarded the gel migration of PCR-generated DNA fragments containing predicted promoters 5' to trsL, trsA, and trsN. The target sequences contained areas of identity, including regions of dyad symmetry, that were protected in DNase I footprinting studies. The binding of TrsN to its trsL target was required for this target DNA to be stably introduced into Staphylococcus aureus on a high-copy-number vector. Provision of excess TrsN from this high-copy-number vector in S. aureus decreased beta-galactosidase activity from a trsL-lacZ transcriptional fusion and decreased pGO1 conjugation frequency. Conversely, both transcription and conjugation increased in the presence of excess trsL target. We propose that TrsN negatively regulates the transcription of genes essential for conjugative transfer by binding to regions 5' to their translational start sites.

The initial vestibulo-ocular reflex and its visual enhancement and cancellation in humans.

The gain (ratio of eye velocity to head velocity) of the initial horizontal vestibulo-ocular reflex (VOR) was calculated in 12 normal subjects over 350 ms during impulsive, unpredictable whole body rotation under three conditions: (1) darkness; (2) visual enhancement of the VOR, while the subjects fixated a stationary target; and (3) visual cancellation of the reflex, while subjects fixated a target that rotated with the head. The gain of the initial 80 ms of compensatory eye movement increased significantly during visual fixation in 5 subjects and decreased during attempted VOR cancellation in 3 subjects, when compared with VOR gain in darkness. Compensatory vestibular smooth eye movements were slowed, becoming curved at the onset of VOR cancellation, at mean latencies ranging from 78 to 149 ms in individual subjects (group mean 128 ms). At about 190 ms, quick phases moved the eyes in the same direction as head and target motion. The subsequent vestibular eye movements were about 50% slower than the initial smooth eye movements, indicating more effective cancellation. Visual enhancement of the VOR can occur prior to the onset of pursuit, providing evidence that fixation and smooth pursuit are distinct ocular motor systems. Visual cancellation of the VOR also begins prior to smooth pursuit initiation and becomes more effective after the latency of smooth pursuit.

Oblique misdirection and slowing of vertical saccades after unilateral lesions of the pontine tegmentum.

Three patients with unilateral lesions of the pontine tegmentum, identified by CT and MRI, had abnormal vertical saccades and slowed ipsilateral horizontal saccades. Attempted vertical saccades were misdirected obliquely, away from the side of the lesion, and their vertical components were prolonged. Oblique saccades had curved trajectories and prolonged durations of their vertical components. Unilateral damage to excitatory burst neurons and pause cells in the medial part of the caudal paramedian pontine reticular formation may cause these abnormal vertical and oblique saccades. Misdirection and slowing of vertical saccades can accompany the paralysis or slowing of ipsilateral horizontal saccades caused by pontine damage.

DNA sequence and units of transcription of the conjugative transfer gene complex (trs) of Staphylococcus aureus plasmid pGO1.

The conjugative transfer genes of 52-kb staphylococcal R plasmid pGO1 were localized to a single BglII restriction fragment and cloned in Escherichia coli. Sequence analysis of the 13,612-base transfer region, designated trs, identified 14 intact open reading frames (ORFs), 13 of which were transcribed in the same direction. Each ORF identified was preceded by a typical staphylococcal ribosomal binding sequence, and 10 of the 14 proteins predicted to be encoded by these ORFs were seen when an E. coli in vitro transcription-translation system was used. Functional transcription units were identified in a Staphylococcus aureus host by complementation of Tn917 inserts that abolished transfer and by Northern (RNA) blot analysis of pGO1 mRNA transcripts. These studies identified three complementation groups (trsA through trsC, trsD through trsK, and trsL-trsM) and four mRNA transcripts (trsA through trsC [1.8 kb], trsA-trsB [1.3 kb], trsL-trsM [1.5 kb], and trsN [400 bases]). No definite mRNA transcript was seen for the largest complementation group, trsD through trsK (10 kb). Comparison of predicted trs-encoded amino acid sequences to those in the data base showed 20% identity of trsK to three related genes necessary for conjugative transfer of plasmids in gram-negative species and 32% identity of trsC to a gene required for conjugative mobilization of plasmid pC221 from staphylococci.

Paresis of contralateral smooth pursuit and normal vestibular smooth eye movements after unilateral brainstem lesions.

Pursuit and vestibular smooth eye movements were measured in patients with lesions of the caudal brainstem tegmentum identified by magnetic resonance imaging (MRI) and computed tomography (CT), with neuropathological correlation in 1 patient. Contralateral smooth pursuit gain was significantly lower than ipsilateral gain in each patient. Ipsilateral smooth pursuit gain was also subnormal in patients with unilateral pontine damage that caused slowing of ipsilateral saccades. Horizontal vestibulo-ocular reflex gain and phase were normal. These quantitative correlations indicate that lesions of the pontine tegmentum that paralyze ipsilateral saccades can spare the vestibulo-ocular reflex, and that smooth pursuit movement and the vestibulo-ocular reflex can be impaired independently by pontine or medullary lesions. In contrast to lesions at other sites, unilateral lesions of the pontine or medullary tegmentum impair contralateral smooth pursuit more than ipsilateral pursuit movements. These findings provide evidence that a double decussating pathway mediates smooth pursuit; the first decussation is from the pons to the cerebellum, and the second decussation is from the vestibular nucleus to the contralateral abducens nucleus.

Spasm of fixation: a quantitative study.

Spasm of fixation, consisting of impaired initiation of saccades in the presence of fixation target, but normal initiation in the absence of a fixation target, was measured in a patient with cerebral hemispheric damage. When a central target was constantly present, the patient made horizontal saccades to the sudden appearance of a second target at very prolonged latencies (mean 369 ms). In the absence of a central fixation target, saccadic latency decreased to normal (197 ms). Extinction of a target for a gap interval elicited very short latency movements (122 ms), termed express saccades. The intervals between self-paced horizontal refixation saccades with the head immobile were prolonged, whereas voluntary refixation saccades with the head free to move occurred at shorter intervals. We postulate that cerebral hemispheric damage may cause spasm of visual fixation by disinhibiting the substantia nigra pars reticulata, thereby inhibiting the superior colliculus.

Effects of energy restriction on norepinephrine turnover and serum glucose and fatty acids in lean mice.

Norepinephrine (NE) turnover rate was determined in several tissues of 5-week-old female mice fed a high carbohydrate diet (58% of energy as carbohydrate, 30% fat) either ad lib or restricted to 34 or 24 kJ/day (36 to 50% restriction) presented as 1 or 2 daily meals. When the restricted intakes were divided into 2 equal meals, daily NE turnover did not differ from that of ad lib-fed mice. When the above restricted amounts were provided as a single daily meal at the beginning of the dark period, NE turnover was 38% and 46% lower, respectively, in the heart only compared to ad lib-fed controls. Serum glucose and total free fatty acids were affected by dietary conditions known to produce sympathetic activation (high carbohydrate and high fat diets) and suppression (high protein diet and energy restriction as a single meal), but the changes were unrelated to fractional NE turnover. Thus, the lower NE turnover seen when food intake is restricted is due to the prolonged overnight fast and not due to the lower energy intake per se, and is not associated with serum concentration of glucose or total free fatty acids.

Psoriatic arthritis and myopathy.

We describe a patient with psoriatic arthritis and a myopathy. The myopathy did not follow the time course of topical steroid treatment, nor did the patient display any features of hypercorticolism or local steroid excess. No evidence was found to support the diagnosis of polymyositis. Psoriatic myopathy is an uncommonly described condition. Steroid induced myopathy shares some nonspecific features with psoriatic myopathy, but can be differentiated by the clinical response to cessation of steroid therapy. Myalgia and 24 h urine creatine elevation are 2 features not previously described in association with psoriatic myopathy. The latter appears to correlate with muscle weakness and may be useful in following the course of this disease.

Internuclear ophthalmoplegia in giant cell arteritis.

Ophthalmoplegia from ischemia to peripheral ocular motor nerves or muscles may complicate the course of giant cell arteritis (GCA). Although brainstem ischemia is known to occur in GCA, internuclear ophthalmoplegia has not been described. Two cases of biopsy-proven GCA are described in which internuclear ophthalmoplegia resulted from brainstem ischemia. Embolization from thrombosed extradural segments of inflammed vertebral arteries, or arteritis of brainstem perforating vessels may account for brainstem infarction. Rapid tapering of steroids was temporally related to brainstem infarction in both cases.