Flower orientation and corolla length as reproductive barriers in the pollinator-driven divergence of Erica shannonea and Erica ampullacea

A variety of reproductive barriers can enable reproductive isolation and stable coexistence of plant species. Differing floral traits might play an important role in reproductive isolation imposed by pollinators. Such shifts in pollinator use have been hypothesized to contribute to the radiation of Erica (Ericaceae) in the Cape Floristic Region, South Africa. The sister species Erica shannonea and Erica ampullacea co-occur and overlap in flowering phenology. Both have unscented long-tubed flowers consistent with adaptations for pollination by long-proboscid flies (LPFs), but differences in flower orientation and corolla tube length are indicative of a shift in pollinator species. We conducted controlled pollination experiments and pollinator observations to determine the breeding system and pollinators of the two species. Both species are self-incompatible and require pollinator visits for seed production, suggesting that pollinators could strongly influence flower evolution. The horizontally orientated flowers of E. shannonea were found to be pollinated by Philoliche rostrata (Tabanidae), which has a long, fixed forward-pointing proboscis, while the vertically upright orientated flowers of E. ampullacea were found to be pollinated by Prosoeca westermanni (Nemestrinidae), which has a shorter proboscis that can swivel downwards. The nemestrinid fly's proboscis is too short to access the nectar in the relative long-tubed flowers of E. shannonea and the tabanid fly's proboscis cannot swivel down to access the upright flowers of E. ampullacea. Consequently, these traits are likely to act as reproductive barriers between the two Erica species and thereby might have contributed to speciation and enable stable coexistence.

Skeletal findings in the first 12 months following initiation of glucocorticoid therapy for pediatric nephrotic syndrome

Incident vertebral fractures and lumbar spine bone mineral density (BMD) were assessed in the 12 months following glucocorticoid initiation in 65 children with nephrotic syndrome. The incidence of vertebral fractures was low at 12 months (6 %) and most patients demonstrated recovery in BMD Z-scores by this time point.

INTRODUCTION

Vertebral fracture (VF) incidence following glucocorticoid (GC) initiation has not been previously reported in pediatric nephrotic syndrome.

METHODS

VF was assessed on radiographs (Genant method); lumbar spine bone mineral density (LS BMD) was evaluated by dual-energy X-ray absorptiometry.

RESULTS

Sixty-five children were followed to 12 months post-GC initiation (median age, 5.4 years; range, 2.3-17.9). Three of 54 children with radiographs (6 %; 95 % confidence interval (CI), 2-15 %) had incident VF at 1 year. The mean LS BMD Z-score was below the healthy average at baseline (mean ± standard deviation (SD), -0.5 ± 1.1; p = 0.001) and at 3 months (-0.6 ± 1.1; p < 0.001), but not at 6 months (-0.3 ± 1.3; p = 0.066) or 12 months (-0.3 ± 1.2; p = 0.066). Mixed effect modeling showed a significant increase in LS BMD Z-scores between 3 and 12 months (0.22 SD; 95 % CI, 0.08 to 0.36; p = 0.003). A subgroup (N = 16; 25 %) had LS BMD Z-scores that were ≤-1.0 at 12 months. In these children, each additional 1,000 mg/m(2) of GC received in the first 3 months was associated with a decrease in LS BMD Z-score by 0.39 at 12 months (95 % CI, -0.71 to -0.07; p = 0.017).

CONCLUSIONS

The incidence of VF at 1 year was low and LS BMD Z-scores improved by 12 months in the majority. Twenty-five percent of children had LS BMD Z-scores ≤-1.0 at 12 months. In these children, LS BMD Z-scores were inversely associated with early GC exposure, despite similar GC exposure compared to the rest of the cohort.

The development of bone mineral lateralization in the arms

Bone mineral content (BMC) is known to be greater in the dominant arm after the age of 8 years. We studied a group of children and found that BMC sidedness gradually increased up to the age of 6 years and then remained stable into late adolescence.

INTRODUCTION

Bone mineral content (BMC) exhibits sidedness in the arms after the age of 8 years, but it is not known whether BMC is greater in the dominant arm from birth or whether lateralization develops in early childhood. To address this, we examined bone mineral status in relation to handedness and age.

METHODS

Subjects (N = 158) were children recently initiating glucocorticoids for underlying disease (leukemia 43 %, rheumatic conditions 39 %, nephrotic syndrome 18 %). Handedness was determined by questionnaire and BMC by dual-energy X-ray absorptiometry.

RESULTS

Median age was 7.2 years (range, 1.5 to 17.0 years), 49 % was male, and the spine BMD Z-score was -0.9 (SD, 1.3). By linear regression, BMC sidedness in the arms was significantly related to age (r = 0.294, p = 0.0005). Breakpoint analysis revealed two lines with a knot at 6.0 years (95 % CI, 4.5-7.5 years). The formula for the first line was: dominant:nondominant arm BMC ratio = 0.029 × age [in years] + 0.850 (r = 0.323, p = 0.017). The slope of the second line was not different from 0 (p = 0.332), while the slopes for the two lines were significantly different (p = 0.027).

CONCLUSIONS

These results show that arm BMC sidedness in this patient group develops up to age 6 years and then remains stable into late adolescence. This temporal profile is consistent with mechanical stimulation of the skeleton in response to asymmetrical muscle use as handedness becomes manifest.

Skeletal findings in children recently initiating glucocorticoids for the treatment of nephrotic syndrome

SUMMARY

Eighty children with nephrotic syndrome underwent lumbar spine densitometry and vertebral morphometry soon after glucocorticoid initiation. We found an inverse relationship between glucocorticoid exposure and spine areal bone mineral density (BMD) Z-score and a low rate of vertebral deformities (8%).

INTRODUCTION

Vertebral fractures are an under-recognized complication of childhood glucocorticoid-treated illnesses. Our goal was to study the relationships among glucocorticoid exposure, lumbar spine areal BMD (LS BMD), and vertebral shape in glucocorticoid-treated children with new-onset nephrotic syndrome.

METHODS

Lateral thoracolumbar spine radiography and LS BMD were performed in 80 children with nephrotic syndrome (median age 4.4 years; 46 boys) within the first 37 days of glucocorticoid therapy. Genant semiquantitative grading was used as the primary method for vertebral morphometry; the algorithm-based qualitative (ABQ) method was used for secondary vertebral deformity analysis.

RESULTS

Six of the 78 children with usable radiographs (8%; 95% confidence interval 4 to 16%) manifested a single Genant grade 1 deformity each. All deformities were mild anterior wedging (two at each of T6, T7, and T8). Four of the 78 children (5%; 95% confidence interval 2 to 13%) showed one ABQ sign of fracture each (loss of endplate parallelism; two children at T6 and two at T8). Two of the children with ABQ signs also had a Genant grade 1 deformity in the same vertebral body. None of the children with a Genant or ABQ deformity reported back pain. An inverse relationship was identified between LS BMD Z-score and glucocorticoid exposure.

CONCLUSIONS

Although we identified an inverse relationship between steroid exposure and LS BMD soon after glucocorticoid initiation for childhood nephrotic syndrome, there was only a low rate of vertebral deformities. The clinical significance of these findings requires further study.

Rodent pollination in the African lily Massonia depressa (Hyacinthaceae)

Field studies in the semiarid Succulent Karoo region of South Africa showed that flowers of Massonia depressa (Hyacinthaceae) are visited at night by at least four rodent species, including two gerbil species. Live-trapped rodents were found to carry Massonia pollen on their snouts; they also had large quantities of Massonia pollen in their feces as a result of grooming their fur. Visits by insects to the flowers were infrequent at one site and apparently absent at another site. Plants enclosed in large-mesh wire cages, which excluded rodents but not insects, set very few seeds relative to open controls. Our initial hypothesis of rodent-pollination in M. depressa was based on the striking similarity of its flowers to those of unrelated, rodent-pollinated Protea species. Convergent traits include dull-colored and very robust flowers situated at ground level, a strong yeasty odor, and secretion of copious amounts of sucrose-dominant nectar during the evening when rodents are active. Despite having a low sugar concentration (∼20%), the nectar of M. depressa is almost 400 times as viscous as an equivalent sugar solution. The jelly-like constituent in the nectar may discourage robbing by insects, while also facilitating lapping by rodents. Our findings illustrate the utility of floral syndromes for generating testable predictions about pollination systems.

Pre-slaughter handling of cattle and Shiga toxin-producing Escherichia coli (STEC)

AIMS

The aim of the study was to monitor the shedding and transmission of generic and Shiga toxin-producing Escherichia coli (STEC) in a consignment of cattle during lot feeding.

METHODS AND RESULTS

Faecal and environmental samples were tested for total E. coli and screened with PCR specific for Shiga toxin and O157 rfb. STEC were isolated using colony hybridization and characterized by serology and genotyping. STEC prevalence initially decreased after the diet shift from pasture to grain, although there were intermittent peaks in numbers of cattle shedding STEC and E. coli O157. Water troughs and soil were intermittently contaminated. Common genotypes and serotypes were isolated from animals, water and soil in the feedlot, with additional types introduced at slaughter.

CONCLUSION

STEC and E. coli O157 are endemic in cattle and intermittent peaks in shedding occur. Prevention of these peaks and/or reduction in transmission is required to reduce the risk of carcass contamination during slaughter.

SIGNIFICANCE AND IMPACT OF THE STUDY

These findings contribute to the understanding of the ecology of STEC and suggest control points for reducing STEC contamination in feedlot cattle production.

Postnatal weight loss and contraction of the extracellular compartment is triggered by atrial natriuretic peptide

Following birth there is a contraction in the extracellular compartment, marked clinically by natriuresis, diuresis and weight loss. It is uncertain how these postnatal phenomena, which suggest an interrelationship with cardiopulmonary adaptation, are brought about. The aim of this study was to evaluate the temporal relationship between alterations in circulating atrial natriuretic peptide (ANP), respiratory status, sodium excretion and extracellular fluid volume (ECFV) in preterm babies, in the first days after birth. Eighteen male infants below 34 weeks gestational age were studied longitudinally, measuring urine output, sodium balance, arterial-alveolar oxygen ratio and circulating ANP. Daily changes in ECFV were assessed by endogenous chloride balance, following baseline measurement of bromide space. There was a clear period of improvement in respiratory function in 15 babies and in these there was a highly significant elevation in circulating ANP, either immediately prior to, or during, the period of improvement. In three infants there was no definable period of respiratory improvement. In four babies, two of whom had very mild respiratory distress, there was an immediate decline in ECFV after birth, in contrast to the remaining 14 infants, in whom there was an initial increase. This study demonstrates that there is a temporal relationship between improvement in respiratory function and an acute elevation in circulating ANP. Babies with respiratory distress syndrome are at risk of initial expansion of the extracellular compartment after birth. This is likely to increase morbidity. These observations are of relevance with regard to the clinical management of newborns with respiratory distress syndrome.

Dynamics of Shiga toxin-producing Escherichia coli (STEC) in feedlot cattle

Feedlot cattle were monitored during fattening to determine changes in faecal shedding of Shiga toxin-producing Escherichia coli (STEC) and their relation to the coliform population. Faecal samples were enriched, screened for Shiga toxin genes (stx) by a polymerase chain reaction test and isolated using colony hybridization. During 117 d in the feedlot, there were differences in the numbers of coliforms shed and in the percentage of samples positive for stx. These fluctuations did not appear to be consistently related to changes in feed or time in the feedlot. The mean log coliform count for stx-positive samples (log 5.85 g-1) was similar to that for stx-negative samples (log 6.00 g-1). The STEC isolates obtained from the first 5 d in the feedlot belonged to eight serotypes. Later, one serotype (O136:H16) became the predominant STEC which appeared to be one clone as characterized by virulence determinants and pulsed-field gel electrophoresis.

A randomised, double-blind study of itraconazole versus placebo in the treatment and prevention of oral or oesophageal candidosis in patients with HIV infection

HIV-infected patients presenting with oral or oesophageal candidosis were randomised to four weeks treatment with itraconazole 200 mg, followed by itraconazole or matching placebo for a prophylaxis phase of 24 weeks. Clinical and mycological evidence of candidosis infection was assessed on a four-weekly basis. Seventy patients were enrolled, of whom 50 completed 28 days of itraconazole therapy; 74% (37 patients) were clinically cured and 40% were also mycologically cured. Fifteen patients were withdrawn for a variety of reasons including non-compliance, adverse events and the use of excluded medications. Forty-four patients were enrolled in the prophylactic phase. There were significantly more relapses of candidosis, and time to candidosis was significantly shorter in the placebo group than in the itraconazole treated group (p = 0.0001). Itraconazole 200 mg daily is effective and well tolerated for the treatment and prevention of oral and oesophageal candidosis in HIV-infected patients.

Non-albicans oral candidosis in HIV-positive patients

Specimens from HIV-positive patients with oral candidosis were taken for culture, species identification and azole susceptibility testing, which was correlated with treatment outcome. Of 921 specimens, 95 yielded non-albicans species, mainly from patients with low CD4 lymphocyte counts and extensive previous azole exposure. Most non-albicans isolates were from specimens co-infected with Candida albicans, complicating the interpretation of in-vitro susceptibility results, which accurately predicted antifungal failure when the non-albicans species was isolated alone. Eighty-five non-albicans isolates were resistant to fluconazole in vitro. Of 149 courses of azole therapy prescribed, 115 failed to clear non-albicans candidosis clinically. Culture media that discoloured in the presence of non-albicans colonies might, therefore, guide therapy.

Treatment of HIV-related fluconazole-resistant oral candidosis with D0870, a new triazole antifungal

OBJECTIVES

To evaluate the efficacy and tolerance of D0870 in the treatment of HIV-related fluconazole-resistant oro-oesophageal candidosis.

DESIGN

Multicentre open study.

PATIENTS

HIV-seropositive patients with oro-oesophageal candidosis despite at least 7 days of treatment with fluconazole at doses of 100 mg per day or more.

METHODS

Patients received an initial dose of D0870 (150 mg), then 25 mg per day for 6 days. Symptoms and signs of candidosis were compared at entry and on days 3 and 7 of treatment. At each visit, samples were taken for safety monitoring and for in vitro susceptibility testing of Candida isolates. Limited pharmacokinetic samples were taken on days 1 and 7.

RESULTS

Of 26 evaluable patients, 16 showed partial improvement, nine showed no improvement, and only one had full clearance of thrush by day 7. In vitro testing of the cleared patient's isolate suggested that it was susceptible to fluconazole. Symptoms of dysphagia cleared in 14 and improved in five of the 22 patients with presumptive oesophageal involvement at entry. Pharmacokinetic measurement showed wide variability in maximum D0870 levels recorded on day 1 (range, 0.07-0.34 mg/l) and susceptibility testing of isolates also showed a range of minimal inhibitory concentration values to D0870 (range, < 0.06-8 mg/l; median, 0.25 mg/l). When these data were combined with clinical response there was a strong suggestion that lack of symptomatic improvement was related to low plasma D0870 levels or to the presence of less D0870-susceptible isolates. Six patients were noted to have a fall in haemoglobin, three of whom were receiving concomitant therapy known to suppress bone marrow. Three patients reported headaches as adverse events that were attributed to study medication, but D0870 was well tolerated overall.

CONCLUSIONS

D0870 shows promise in the treatment of fluconazole-resistant oro-oesophageal candidosis and was well tolerated, although efficacy in this difficult-to-treat patient group was probably limited due to the inadequate plasma levels achieved in this pilot study with the low doses of D0870 administered.

Clinically significant azole cross-resistance in Candida isolates from HIV-positive patients with oral candidosis

OBJECTIVES

To determine the proportion of fluconazole-resistant Candida albicans isolates that have clinically significant cross-resistance to itraconazole or ketoconazole, that is sufficient to result in failure of these agents at their standard doses (200 and 400 mg daily for 7 days, respectively).

METHODS

Seven hundred C. albicans isolates from HIV-positive patients with oral candidosis underwent susceptibility testing using a relative growth method, for which cut-off values corresponding to clinical drug failure have been established.

RESULTS

A total of 431 isolates were fully azole-susceptible and three main resistance patterns were detected: isolates resistant to fluconazole alone (n = 100); isolates resistant to fluconazole and ketoconazole but susceptible to itraconazole (n = 94); and isolates resistant to all three drugs (n = 50). No isolates were consistently resistant to ketoconazole without being fluconazole-resistant, and no itraconazole resistance was detected without ketoconazole resistance. Resistance to fluconazole alone was more common in specimens obtained soon after first clinical fluconazole failure, whereas specimens from patients with a longer history of fluconazole-unresponsive candidosis were more likely to be infected with cross-resistant isolates. Median days of prior azole exposure and cumulative fluconazole dose were significantly less for those with isolates resistant to fluconazole alone than for those with ketoconazole cross-resistant isolates, who had received less azole therapy and smaller cumulative fluconazole doses than those with isolates cross-resistant to all three drugs (although not statistically significant). After the diagnosis of fluconazole-unresponsive candidosis, increasing cumulative doses of itraconazole solution were associated with increasing likelihood of cross-resistance.

CONCLUSIONS

Clinically significant cross-resistance to other azoles may occur in fluconazole-resistant isolates of C. albicans, although initially most isolates are not cross-resistant and the detection of cross-resistant isolates is associated with a history of greater prior azole exposure. Patients who have been treated for fluconazole-resistant candidosis for longer and with greater cumulative doses of itraconazole solution tend to become infected with increasingly cross-resistant isolates of C. albicans.

Prior fluconazole exposure as an independent risk factor for fluconazole resistant candidosis in HIV positive patients: a case-control study

OBJECTIVES

To determine if prior fluconazole exposure was an independent risk factor for fluconazole resistant candidosis in HIV positive patients.

METHODS

Twenty five HIV positive cases with fluconazole resistant oral candidosis were matched by CD4 lymphocyte count and time since first episode of candidosis to 25 HIV positive controls with susceptible candidosis. For each individual a history of prior azole prophylaxis was compiled from computerised pharmacy records and review of case notes.

RESULTS

The total days of prior azole therapy prescribed was significantly greater for cases than controls. These differences were attributable to prescriptions for secondary prophylaxis against recurrent candidosis, the cases having received significantly longer continuous azole prophylaxis than controls, with no difference in days of prior azole therapy remaining between the two groups if prophylactic prescriptions were excluded. The total cumulative dose of fluconazole received was significantly higher for cases than controls, though mean daily fluconazole doses did not differ significantly between the two groups.

CONCLUSION

Even after controlling for degree of immunosuppression and duration of recurrent candidosis, the association between prior azole exposure and fluconazole resistant candidosis remains significant and largely reflects differences in the prescription of secondary antifungal prophylaxis.

Unresponsive HIV-related oro-oesophageal candidosis--an evaluation of two new in-vitro azole susceptibility tests

Azole-resistant HIV-related candidosis is increasingly recognized. We evaluated two new in-vitro susceptibility tests (the NCCLS proposed MIC method and Odds' assessment of relative growth in single anti-fungal concentration) as predictors of the clinical outcome of 66 HIV-positive patients with oral candidosis, of whom 22 were azole naive, 27 had always previously responded to azole therapy and 17 had persistent candidosis unresponsive to 7 days of standard azole therapy. None of the last group responded to increased daily doses of fluconazole or itraconazole capsules, though nine responded to itraconazole cyclodextrin solution 200 mg bd for 7 days. Our findings suggest that agreement between the Odds' test and the MIC method was excellent (96-98%) and that both could discriminate between isolates of azole-unresponsive patients and those of azole-responsive patients. For fluconazole susceptibility an MIC > or = 8 mg/L detected fluconazole-unresponsive patients with a sensitivity of 94% and specificity of 100%; Odds' method achieved 100% sensitivity and 100% specificity using all cut-offs between 77 and 88% relative growth in medium containing fluconazole (10(-5) M; 3 mg/L). For itraconazole and ketoconazole agreement between MIC and Odds' method was again excellent (98% and 96%, respectively) but five azole-unresponsive patients appeared to have ketoconazole-susceptible organisms as defined by both tests, and similarly 11 appeared to have itraconazole-susceptible organisms by both tests despite failing to respond to the capsule formulation of the drug. Of these 11, eight responded to itraconazole solution; this finding implies that itraconazole capsule failure might represent poor drug absorption rather than fungal resistance.

Clinical response to ketoconazole of HIV-related oral candidosis is predicted by Odds' relative growth method of susceptibility testing

In-vitro ketoconazole susceptibility was assessed by measuring an isolate's relative growth in medium containing a fixed concentration of ketoconazole as a percentage of growth in drug-free medium. One hundred specimens from HIV-positive patients with candidosis were tested. Each patient's response was assessed following one week's treatment with ketoconazole 400 mg/day. A relative growth in ketoconazole of >75% predicted clinical failure of ketoconazole with a specificity of 97% and sensitivity of 79%.

Fly pollination of Gorteria diffusa (Asteraceae), and a possible mimetic function for dark spots on the capitulum

We investigated the functional significance of raised black spots on the ray florets of Gorteria diffusa (Asteraceae) in South Africa. Field observations showed that G. diffusa is pollinated by a small bee-fly, Megapalpus nitidus (Bombyliidae), which is strikingly similar to the raised spots that occur on some of the ray florets. Removal of the spots resulted in a significant decrease in the rate of fly visits to capitula, but did not significantly affect seed set. Replacement of the spots with simple ink spots also significantly reduced the rate of pollinator visits, suggesting that flies respond to details in the structure of the spots. Investigations using scanning electron microscopy showed that the spots of G. diffusa consist of a complex of different cell types. Differences in epidermal sculpturing may partly explain the UV reflectance pattern of these spots, which is similar to that of the flies. Male flies are strongly attracted to the spots, as well as to other flies sitting in the capitula, although female flies also visit the capitula. We conclude that the spots of G. diffusa mimic resting flies, thereby eliciting mate-seeking and aggregation responses in fly pollinators. Similar dark spots have evolved in unrelated South African Gazania, Dimorphotheca, and Pelargonium species pollinated by bee-flies.

Itraconazole cyclodextrin solution: the role of in vitro susceptibility testing in predicting successful treatment of HIV-related fluconazole-resistant and fluconazole-susceptible oral candidosis

OBJECTIVES

This study assessed the ability of in vitro susceptibility testing of clinical Candida isolates to predict in vivo response to itraconazole cyclodextrin solution.

METHODS

One hundred specimens were obtained from HIV-positive patients with oral thrush, of which 72 speciments were from patients who were clinically unresponsive to fluconazole at standard doses and had fluconazole-resistant isolates in vitro. Susceptibility to itraconazole was assessed by measuring the relative growth of an isolate in liquid medium containing a single concentration of itraconazole and then expressing growth in itraconazole as a percentage of growth in antifungal-free medium.

RESULTS AND CONCLUSIONS

Where specimens yielded only one isolate, a cut-off relative growth in itraconazole of 68% discriminated between isolates from patients failing to respond clinically to itraconazole solution and those from patients successfully treated with the preparation (specificity 100%; sensitivity 88%). The presence of mixed infection reduced the predictive accuracy of the test. Only 30% of fluconazole-resistant isolates were cross-resistant to itraconazole. No isolates were resistant to itraconazole but susceptible to fluconazole. Non-response to itraconazole solution was attributed to resistant yeast infection in the majority of cases, and this susceptibility method accurately identified specimens from patients unlikely to respond to the drug.

Use of terbinafine in HIV-positive subjects: pilot studies in onychomycosis and oral candidiasis

Study 1. Eighteen HIV-positive Caucasian homosexual men with initial positive fungal microscopy were recruited into this prospective, dual-centre, open-label study. They received a once-daily oral dose of 250 mg terbinafine for 12 weeks. Eight were subsequently excluded after screening cultures proved negative. The mean CD4 count of the 10 evaluable subjects was 302/mm3. All 10 positive fungal cultures were confirmed as Trichophyton rubrum. Using an intention-to-treat analysis, healthy unaffected nail growth increased from a mean of 1.6 mm at baseline to 5.2 mm after 12 weeks' treatment. Clinical response after treatment was 6.4 mm at 36 weeks and 8.0 mm at 48 weeks. Three of the 10 toenail infections were cured mycologically. This 30% cure rate was maintained over 48 weeks' follow-up, despite three patients discontinuing the study. One withdrew following a terbinafine-induced drug rash. Two others stopped treatment during HIV-related illnesses, but without terbinafine side-effects. Study 2. Ten HIV-positive subjects, nine culture-positive for Candida albicans and one for Candida albicans and Candida glabrata, were recruited into this pilot study. They received 250 mg oral terbinafine daily for 14 days. Their average CD4 count was 131/mm3. All patients remained culture-positive throughout the study. Slight improvements in signs and symptoms were seen in one or two patients but this might well have been attributable to improved oral hygiene. Oral terbinafine at this dosage was therefore not thought an effective treatment for this indication in HIV-positive patients. The drug was well tolerated and no serious treatment-related adverse events were reported.

Relative growth measurement of Candida species in a single concentration of fluconazole predicts the clinical response to fluconazole in HIV infected patients with oral candidosis

The growth of 113 Candida spp. isolated prospectively from 104 HIV-positive patients treated for thrush was determined using a single concentration of 3 mg/L (10(-5) M) fluconazole relative to growth in drug free medium. Using a receiver operator characteristic curve, a relative growth in fluconazole of > or = 88% best discriminated between isolates from 56 patients who responded to treatment with fluconazole and 48 who failed to respond to 7 days, treatment with at least 100 mg/d drug with a sensitivity of 98% and a specificity of 96%. When the isolates from the eight patients with mixed infections due to both resistant and susceptible yeasts were excluded, the sensitivity and specificity both reached 100%. Relative growth of Candida spp. in a single concentration of fluconazole can therefore be used to accurately predict the clinical response to standard fluconazole treatment of thrush in patients infected with HIV.

Serum bromide measurements in infants below 1000 g, for determination of corrected bromide space

We describe modifications to the gold colorimetric method for the measurement of serum bromide in the estimation of extracellular fluid volume. These modifications allow the application of the bromide dilution technique to small infants, below 1000 g birth weight, since sample volumes as small as 50 microliters may be assayed.

Atrial natriuretic peptide, cyclic guanosine monophosphate and sodium excretion during postnatal adaptation in male infants below 34 weeks gestation with severe respiratory distress syndrome

The role of atrial natriuretic peptide (ANP), in the perinatal period, is at present unclear. In adults urinary cyclic guanosine monophosphate (cGMP) is considered an index of the biological activity of plasma ANP. The aim of this study was to determine the relationship between plasma ANP, cGMP excretion (cGMPex) and sodium excretion (Naex) in preterm infants in the first days after birth. Sequential, 4 hourly, measurements of plasma ANP, cGMPex and Naex were made in 12 male neonates of median gestational age 27 weeks (range 25-33) and median birth weight 0.981 kg (range 0.635-2.029) over a median period of 5.2 days (range 2.3-10). The ratios of cGMPex to ANP and of Naex to cGMPex were each plotted against postnatal age. The ratio of cGMPex to ANP increased ten fold in the first 3-4 days after birth but then remained relatively constant; the ratio of Naex to cGMPex showed a steady increase from birth. We conclude that, in extremely immature infants, renal sodium loss in response to cGMP increases rapidly during the first 10 days after birth. In addition, after 3-4 days from birth, plasma ANP ia associated with a constant proportionate rate of cGMP excretion though, as the plateau ratio of cGMPex to ANP varied widely between babies, cGMPex cannot be used to predict plasma ANP in cross sectional studies. These changes may reflect postnatal adaptation and/or maturation of both ANP receptors and cGMP mediated cascades. In the immediate postnatal period, plasma ANP may also have a non-renal role.

Itraconazole versus ketaconazole in the treatment of oral and oesophageal candidosis in patients infected with HIV

To determine the efficacy and toxicity of two systemically active antifungal agents in the treatment of buccal and oesophageal candidiasis 111 HIV-infected patients with microscopically-confirmed candidiasis were randomized to receive either 200 mg itraconazole once a day or 200 mg ketoconazole twice a day for 28 days in a double blind study. After 1 week of treatment, 75 and 82% of the patients on itraconazole and ketoconazole, respectively, had responded clinically. After 4 weeks of treatment, this had risen to 93% in each group. One patient discontinued itraconozole because of toxicity (rash), five patients discontinued ketaconazole (two nausea, two hepatotoxicity and one rash). Despite successful clinical and mycological clearance, 80% patients had a further episode of candidosis within the next 3 months.

Disseminated histoplasmosis in an AIDS patient treated with itraconazole

A patient with AIDS presented with a fever, shortness of breath and a productive cough. A provisional diagnosis of Pneumocystis carinii pneumonia was made; however, blood cultures and bone marrow examination revealed disseminated infection with Histoplasmosis capsulatum. This was treated by itraconazole with initial success, but the patient relapsed while on maintenance therapy.

Monoclonal immunofluorescence compared with silver stain for investigating Pneumocystis carinii pneumonia

Two hundred and eighty two specimens from 220 patients positive for HIV with respiratory tract symptoms, or febrile illness, or both, were examined for the presence of Pneumocystis carinii. Specimens were either induced sputum samples or bronchoalveolar lavage fluids. To establish the optimal method for laboratory diagnosis a comparison was made of detection of the organism by use of monoclonal antibody and immunofluorescence with conventional silver staining methods. Three commercially available reagents for immunofluorescence were also compared. Immunofluorescence was significantly more sensitive than the silver stain and the best results for immunofluorescence were obtained using. Northumbria Biologicals Ltd reagents.

Gonococcal arthritis caused by auxotype P in a man with HIV infection

The development of gonococcal arthritis is reported in a man with HIV infection and CDC Stage IVC2 disease. The diagnosis of disseminated Neisseria gonorrhoeae was facilitated by microbiological examination of a joint aspirate. The auxotype identified by culture was moderately resistant to penicillin, a characteristic which is highly unusual for an organism causing disseminated gonococcal infection. This case serves as an example of the role of HIV infection in the modification of host response to common pathogens and the need for clinicians to modify their management of disseminated gonococcal infection especially in immunosuppressed persons.

Candida and AIDS: evidence for protective antibody

Clinical observation and animal models of candidosis suggest that, although T lymphocytes are important in preventing superficial candidosis, defence against systemic candidosis depends upon humoral immunity. An antibody response to the immunodominant 47 kD antigen of Candida albicans is invariably associated with recovery. The presence of this antibody in patients with chronic mucocutaneous candidosis and the acquired immunodeficiency syndrome (AIDS) could account for the rarity of disseminated candidal infection in these conditions. Polyclonal B cell activation may be responsible for the frequency with which this antibody is produced in AIDS. Antibody to the 47 kD antigen could be useful in the treatment and prevention of systemic candidosis, though not in the superficial candidosis of AIDS.

Parvovirus infection in hospital practice

Eleven cases of human parvovirus (HPV) infection were diagnosed on the basis of positive IgM serology over a 9-month period in two London hospitals. These cases accounted for almost 30% of viral illness in which HPV serology had been requested. Ten of the cases presented with joint symptoms and/or rash and one case presented with evidence of a severe autoimmune haemolytic anaemia. Six patients had lymphadenopathy. Clinical and laboratory features of the cases are presented. HPV DNA was sought but not found in synovial fluid from one patient.

Control of a hospital outbreak of methicillin-resistant Staphylococcus aureus infections: value of an isolation unit

An outbreak of methicillin- and gentamicin-resistant Staphylococcus aureus infections started in a university hospital after a patient, who was not known to be colonized, was admitted. During a 3-month period 15 surgical or geriatric patients and five staff were found to be infected or colonized by the epidemic strain in five surgical/orthopaedic wards, a geriatric ward, the intensive care unit and the isolation unit. Difficulties in controlling the outbreak arose when two patients who initially had negative bacteriological screening results were returned to general wards. Both patients were subsequently shown to be colonized and caused outbreaks which led to the further closure of two general wards. There was strong circumstantial evidence to suggest that physiotherapy staff were involved with the spread of the epidemic strain. Control of the outbreak was achieved by more strict isolation of 'negative' patient contacts as well as colonized/infected patients and increasing the level of staffing on the separate isolation unit.

Streptobacillus moniliformis isolated from blood in four cases of Haverhill fever

During February, 1983, an outbreak of an unusual febrile illness occurred in over 130 children attending a boarding school in Chelmsford, Essex. The clinical features included fever, an erythematous rash that was most prominent on the hands and feet, arthralgia, and the subsequent development of a sore throat. The nature and distribution of the rash varied considerably between patients and at different stages of illness. At first a viral aetiology was regarded as most likely. When Streptobacillus moniliformis was later isolated from the blood of 4 of the patients with moderately severe illnesses it became apparent that an outbreak of Haverhill fever had occurred at this school. The most probable source of the outbreak was raw milk, since all 4 patients had consumed raw milk at the school shortly before the onset of symptoms and there was no evidence of person-to-person spread of infection.

Developmental roles for social work in the Third World: the prospect of social planning

Many social workers today are critical of what they regard as their profession's conventional concern with remedial social welfare. This criticism has been voiced with special reference to developing countries, and some social workers have suggested alternative roles for social work in the third world. Among these it has been suggested that social workers should take prime responsibility for social development planning in the developing countries. But this suggestion is unrealistic. Social workers are not likely to be asked to participate in national social policy formulation and planning until they have legitimized their claim to professional status and public recognition and demonstrated their ability to deal with the pressing problems of poverty in the third world through direct service.