Acid-alcohol fast bacilli in sputa of HIV-infected patients

We identified 34 HIV-infected patients with sputum smear positive for acid-alcohol fast bacilli (AAFB) to determine any factors predictive of subsequent species identification. There were 20 cases of Mycobacterium tuberculosis (MTB), 9 cases of Mycobacterium avium-intracellulare (MAI), 3 cases of Mycobacterium kansasii and one each of Mycobacterium malmoense and Mycobacterium fortuitum. Factors associated with isolation of MAI were lower CD4 cell count, a higher incidence of previous AIDS diagnosis, a history of dyspnoea and a normal chest X-ray. The organism was isolated from blood cultures in 58% of patients with MTB and 78% of patients with MAI infection. Disseminated disease was diagnosed in 45% of MTB patients and 33% of MAI patients.

ICU admission in patients infected with the human immunodeficiency virus - a multicentre survey

We conducted a retrospective study to assess the reasons for admission to the intensive care unit, and subsequent outcome, in patients infected with the human immunodeficiency virus (HIV). Four hospitals in the south of England participated, all with specialist HIV units. Data were collected on 127 patients admitted to ICU on 133 separate occasions between June 1993 and October 1997. The mean age on admission was 38 years (range 23-60 years). Ninety-four patients (70.7%) were documented HIV-positive before admission and 36 (27%) were diagnosed HIV-positive for the first time during admission; 36.1% were admitted with Pneumocystis carinii pneumonia. Overall ICU mortality was 33%, in-hospital mortality was 56% and the eventual mortality at the end of follow-up (March 1998) was 72%. Survival was highest in those admitted with respiratory HIV-related disease or HIV-unrelated illness. Associations with poor outcome included a prior AIDS-defining illness, a CD4 cell count of less than 100 cells.ml-1 and admission secondary to sepsis.

Influence of apolipoprotein E genotype variation on the means, variances, and correlations of plasma lipids and apolipoproteins in children

The impact of the three most common apolipoprotein E (APOE) genotypes (epsilon 32, epsilson 33, and epsilon 43) on means, variances, and correlations of nine plasma lipid and apolipoprotein traits (total cholesterol, InTriglycerides, HDL cholesterol, and apolipoproteins AI, AII, B, CII, CIII, and InE) was studied in 212 unrelated female and 219 unrelated male children aged 5-21.5 years from 278 pedigrees ascertained without regard to health status from Rochester, Minnesota. There was significant heterogeneity (p < or = 0.05) among genotypes for the mean plasma levels of InApo E, Apo CII, Apo CIII, and InTriglycerides (InTrig) in females, and for the means of InApo E, Apo B, and total cholesterol (Total-C) in males. Significant heterogeneity of intragenotypic variance was observed in males for Apo CII, InTrig, and HDL-C; no significant heterogeneity was observed in females. Pairwise correlations between traits differed significantly among APOE genotypes in both females (6 of 36 pairs) and males (5 of 36 pairs). These results differ from those obtained from studies of the parental generation from the same sample of pedigrees. Our study further demonstrates that, with the exception of mean InApo E levels, the univariate and bivariate distributions of traits that are measures of lipoprotein metabolism are influenced by variation in the APOE gene in a gender- and generation-dependent manner.

Evaluation of sperm washing as a potential method of reducing HIV transmission in HIV-discordant couples wishing to have children

OBJECTIVE

A number of discordant couples, in whom the man is HIV positive and the woman is HIV negative, wish to have children. To conceive they must abandon protected sex, posing a risk of HIV transmission to the woman and so to the child. In such circumstances purification of spermatozoa ('sperm-washing') to inseminate the woman artificially has been proposed as a method of reducing the risk of transmission. Here we evaluate whether this does represent a true risk reduction.

METHODS

Semen samples from HIV-positive patients were separated into spermatozoa, non-sperm cells (NSCs) and plasma fractions. The amount of viral RNA present in each fraction was measured and compared with the level in the peripheral blood. Each fraction was also assessed for the presence of proviral DNA. The ability of spermatozoa to be infected was assessed by evaluating for the presence of HIV receptors, i.e. CD4, CCR5 and CXCR4 on the surface of the sperm, by flow cytometry.

RESULTS

A poor correlation was found between the levels of HIV in blood and semen. Within the semen the virus was restricted to the plasma and/or NSCs. All spermatozoa were negative for viral RNA or proviral DNA. Spermatozoa did not express significant levels of CD4, CCR5 or CXCR4, suggesting that they are unlikely to be major targets for HIV infection.

CONCLUSIONS

These data suggest that spermatozoa are not major targets of HIV infection. Purifying spermatozoa reduced the level of HIV RNA and proviral DNA to below the detection limit of the assays irrespective of the amount of virus present in the unfractionated semen. On the basis of these data we would recommend 'sperm-washing' followed by insemination as a safer alternative to natural conception for HIV-discordant couples wishing to have children.

Measurement and classification of retinal vascular tortuosity

Automatic measurement of blood vessel tortuosity is a useful capability for automatic ophthalmological diagnostic tools. We describe a suite of automated tortuosity measures for blood vessel segments extracted from RGB retinal images. The tortuosity measures were evaluated in two classification tasks: (1) classifying the tortuosity of blood vessel segments and (2) classifying the tortuosity of blood vessel networks. These tortuosity measures were able to achieve a classification rate of 91% for the first problem and 95% on the second problem, which confirms that they capture much of the ophthalmologists' notion of tortuosity. Finally, we discuss how the accuracy of these measures can be influence by the method used to extract the blood vessel segments.

Effect of isometric contraction on threshold somatosensory evoked potentials

We previously described the augmentation of sensory nerve action potential amplitudes after near and remote isometric muscle contraction. In this study, we wished to determine if the sensory cortex was involved in this process. In this prospective, intrinsically controlled study, we studied threshold somatosensory evoked potentials in 12 normal subjects with stimulation of the median nerve at 5.1 Hz. The subjects were tested during the following conditions: baseline, 25%, and 75% maximum isometric abductor digiti minimi contraction for 4 min. Each of these conditions was recorded before, during, and 4 min and 8 min after contraction. Results showed that at 25% contraction, there was a significant temporal increase in N9 amplitude (2.1-2.6 microV; P = 0.05, analysis of variance, repeated measures) and a decrease in N20 amplitude with 75% contraction (1.9-1.6 microV; P = 0.03, analysis of variance, repeated measure). No significant changes were noted in the spinal cord or brainstem recordings. In conclusion, it appears that augmentation of the brachial plexus peripheral nervous system recording occurs concurrently with central inhibitory gating. The possibility of peripheral nervous system adaptability will be discussed.

Structures of EF-hand Ca(2+)-binding proteins: diversity in the organization, packing and response to Ca2+ binding

The growing database of three-dimensional structures of EF-hand calcium-binding proteins is revealing a previously unrecognized variability in the conformations and organizations of EF-hand binding motifs. The structures of twelve different EF-hand proteins for which coordinates are publicly available are discussed and related to their respective biological and biophysical properties. The classical picture of calcium sensors and calcium signal modulators is presented, along with variants on the basic theme and new structural paradigms.

An outbreak of methicillin-resistant Staphylococcus aureus (MRSA) infection in HIV-seropositive persons

Staphylococcus aureus is a cause of considerable morbidity and mortality in HIV-seropositive persons. Although methicillin-resistant S. aureus (MRSA) is encountered worldwide and in many areas of medical care, little has been reported on clinical infection with MRSA in patients with HIV. We report on an outbreak of MRSA infection in HIV antibody positive patients, using case reports to describe an outbreak of MRSA infection in HIV-seropositive persons. Six cases of clinical MRSA infection were reported over a 4-week period on patients on an HIV dedicated ward. All cases had previous AIDS diagnoses and low CD4 cell counts (median 8 x 10(6)/l; range 0 to 238). Two cases had infected skin lesions and 2 cases had infected indwelling central venous catheters with septicaemia. Two cases had pneumonia, one with concurrent infection at the entry site of a percutaneous endoscopic gastrostomy (PEG) feeding tube. Isolates of MRSA from the 6 cases were compared by pulsed-field gel electrophoresis of Sma1 chromosomal digests. The resultant banding pattern showed the same strain was responsible for all the infections. A seventh inpatient, the index case, had positive carriage with the same strain of MRSA. To define ongoing MRSA carriage after the outbreak, 29 consecutive ward patients were swabbed for MRSA: all were negative. All patients identified with MRSA infection responded to treatment with intravenous teicoplanin, although carriage was unaltered. Four of the 6 cases died within 7 weeks of diagnosis of MRSA. MRSA can cause severe morbidity in patients with end-stage HIV disease. A small outbreak of MRSA was controlled by simple precautionary measures with no subsequent ongoing transmission of MRSA.

Brachial plexus birth injuries and current management

OBPP is a condition that, for the majority of patients, resolves spontaneously with appropriate nonoperative treatment. However, those patients who do not improve spontaneously now have a better chance for recovery owing to recent advances in microsurgery and nerve-transfer techniques. The most important aspect of therapy is timely recognition and referral.

Safety, pharmacokinetics, and antiretroviral activity of the potent, specific human immunodeficiency virus protease inhibitor nelfinavir: results of a phase I/II trial and extended follow-up in patients infected with human immunodeficiency virus

The safety, antiretroviral activity, and pharmacokinetic profile of nelfinavir, a potent and specific inhibitor of human immunodeficiency virus (HIV) protease, were assessed in a small open-label phase I/II dose-ranging study in protease inhibitor-naive HIV-positive men. A total of 22 patients with baseline plasma HIV RNA > or = 20,000 copies/mL and CD4+ counts between 200 and 500 cells/mm3 were enrolled in the study. Of the 22 patients, 20 were evaluated for activity; 10 patients assigned to 771 mg/day base equivalent (300 mg three times daily) and 10 patients assigned to 1,026 mg/day base equivalent (600 mg twice daily) given monotherapy. A capsule formulation of nelfinavir was used. The initial study period was 28 days; patients showing a virologic response of 1 log10 reduction were eligible for enrollment in an extension phase and addition of nucleoside analogues. A maximally tolerated dose of nelfinavir was not established. A dose-response relationship was observed for four (40%) patients in the 771-mg group and six (60%) patients in the 1,026-mg group experiencing a reduction from baseline in plasma HIV RNA of at lest 1 log during the 28-day study. Of these patients, five sustained the reduction in plasma HIV RNA beyond day 28 (2 patients receiving 771 mg/day and 3 patients receiving 1,026 mg/day). Median increases from baseline in CD4+ counts at day 28 were 216 cell/mm3 and 86 cell/mm3 in the 771-mg and 1,026-mg groups, respectively. After oral administration, median nelfinavir plasma concentrations on day 28 reached a maximum at 1 hour (2,966 ng/mL) in the 771-mg group and at 3 hours (3,157 ng/mL) in the 1,026-mg group. Data for 22 patients were included in the safety analysis; 12 patients (55%) reported at least one grade 2 or worse (moderate, severe, or very severe) adverse event. The most common grade 2 or worse adverse event was diarrhea, reported by two patients (20%) receiving 771 mg/day and seven patients (70%) receiving 1,026 mg/day; followed by nausea, flatulence, asthenia, and headache (each reported in 1 patient [10%] in the 771-mg group) and dizziness (reported in 1 patient [10%] receiving 1,026 mg/day). In the small subgroup (n = 6) who continued taking nelfinavir for longer periods (between 8 and 15 months), virologic responses were sustained in the majority of patients with good tolerability. Nelfinavir is an active HIV-protease inhibitor with favorable pharmacokinetics, good tolerability, and sustained antiviral effects. Results of this early phase I/II dose-ranging study provided data for the safety and antiretroviral activity of nelfinavir and led to the selection of higher doses for phase II/III trials to further optimize virologic and immunologic responses.

An interaction-based analysis of calcium-induced conformational changes in Ca2+ sensor proteins

Calcium sensor proteins translate transient increases in intracellular calcium levels into metabolic or mechanical responses, by undergoing dramatic conformational changes upon Ca2+ binding. A detailed analysis of the calcium binding-induced conformational changes in the representative calcium sensors calmodulin (CaM) and troponin C was performed to obtain insights into the underlying molecular basis for their response to the binding of calcium. Distance difference matrices, analysis of interresidue contacts, comparisons of interhelical angles, and inspection of structures using molecular graphics were used to make unbiased comparisons of the various structures. The calcium-induced conformational changes in these proteins are dominated by reorganization of the packing of the four helices within each domain. Comparison of the closed and open conformations confirms that calcium binding causes opening within each of the EF-hands. A secondary analysis of the conformation of the C-terminal domain of CaM (CaM-C) clearly shows that CaM-C occupies a closed conformation in the absence of calcium that is distinct from the semi-open conformation observed in the C-terminal EF-hand domains of myosin light chains. These studies provide insight into the structural basis for these changes and into the differential response to calcium binding of various members of the EF-hand calcium-binding protein family. Factors contributing to the stability of the Ca2+-loaded open conformation are discussed, including a new hypothesis that critical hydrophobic interactions stabilize the open conformation in Ca2+ sensors, but are absent in "non-sensor" proteins that remain closed upon Ca2+ binding. A role for methionine residues in stabilizing the open conformation is also proposed.

Progressive multifocal leukoencephalopathy in HIV

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by infection of oligodendrocytes by JC virus. As patients with HIV survive longer with severe immunodeficiency, the incidence of PML is rising. Diagnosis is not always easy and the gold standard remains histological confirmation of the characteristic lesions of PML which requires a brain biopsy. This is considered too invasive by many clinicians and patients alike and detection of JC virus DNA in the cerebrospinal fluid (CSF) using polymerase chain reaction (PCR) is used as an alternative to biopsy. JC virus subtype detection in brain, CSF and blood leukocytes may offer further diagnostic and prognostic possibilities. The aetiology, clinical features and diagnostic problems of PML are reviewed. At present the outlook for patients with confirmed PML is poor and there is currently no effective treatment. However, novel approaches to treatment are under investigation and show some promise.

Central venous line infections in AIDS

The relative infection rates of Port-a-Cath and Hickman lines used for the maintenance treatment of cytomegalovirus retinitis were studied by retrospective casenote review. Seventy-five lines were inserted over an 18 month period. The overall infection rates were significantly greater for Hickman lines: 0.97/100 line-days compared to 0.39/100 line-days for Port-a-Caths, with a trend towards higher infection rates in those prescribed ganciclovir. A total of 56 episodes of septicaemia were recorded with a significantly greater incidence of septicaemia within 1 month of line insertion in those with a neutrophil count < 1.0 x 10(3)/mm3. Ten infectious episodes were associated with death, six of which were due to Pseudomonas spp.

CONCLUSIONS

In HIV seropositive patients, use of a Port-a-Cath is associated with a significantly lower rate of line associated sepsis than use of a Hickman line. Insertion of long term central venous catheters should be avoided if possible when the neutrophil count is < 1.0 x 10(3)/mm3.

Augmented sensory nerve action potentials during distant muscle contraction

We previously reported that the median sensory nerve action potentials (SNAP) increased in amplitude during ipsilateral abductor pollicis brevis contraction. The objectives of the present project were to study the timing and origin of this phenomenon and to eliminate the possibility of local artifact. Ten normal subjects were recruited. The baseline was established using ten threshold stimuli, which were delivered to the median nerve at the wrist at 0.2 Hz. Using the same stimulus strength, the SNAP was recorded while the tibialis anterior was contracted at 25, 50, 75, and 100% of maximum force. Responses were signal-averaged. Results showed an increase in ipsilateral SNAP amplitude between baseline and maximum contraction of 6 +/- 2 microV (standard error, P = 0.004) and contralateral amplitude of 8 +/- 2 microV (standard error, P = 0.01). Statistical analysis was performed with analysis of variance for repeated measures and paired t test. The effect peaked between 0 and 10 min after contraction and lasted from 1.5 to more than 20 min after muscle relaxation. In conclusion, SNAP appear to be enhanced during and after muscle contraction. Theories concerning underlying causes for this event are discussed.

Automated measurement of retinal vascular tortuosity

Automatic measurement of blood vessel tortuosity is a useful capability for automatic ophthalmological diagnostic tools. We describe a suite of automated tortuosity measures for blood vessel segments extracted from RGB retinal images. The tortuosity measures were evaluated in two classification tasks: (1) classifying the tortuosity of blood vessel segments and (2) classifying the tortuosity of blood vessel networks. These tortuosity measures were able to achieve a classification rate of 91% for the first problem and 95% on the second problem, which confirms that they capture much of the ophthalmologists' notion of tortuosity.

Energy balance in asymptomatic HIV infection

OBJECTIVES

Body weight is regulated by the balance between energy intake and energy expenditure, but the influence of HIV infection on energy balance has not been fully examined. The main objectives of this study were (1) to assess the effect of HIV on energy balance, (2) to examine the relationship of parameters of immunodeficiency to energy balance, and (3) to examine the interrelationship of different components of energy balance in asymptomatic HIV-seropositive men.

DESIGN

A cross-sectional study of nutrition and metabolism in asymptomatic HIV-seropositive men

METHODS

Components of energy balance were examined in 104 asymptomatic HIV-seropositive men (CD4 count 4-482 x 10(6)/l) and 57 age-matched HIV-seronegative male controls. Energy and protein intake were measured using 5-day diaries, and small bowel absorption and permeability was assessed using four sugar probes. Resting energy expenditure was calculated from indirect calorimetry and nitrogen loss estimated from 24 h urine collection. Four methods were used to assess the effect of HIV infection on body composition (anthropometry, dual energy X-ray absorptiometry, bioelectrical impedance and 24 h urine creatinine).

RESULTS

Resting energy expenditure per kilogram of fat-free mass was raised (P < 0.0001), fat mass was decreased (P = 0.001), fat-free mass was increased (P = 0.05), energy intake was higher (P = 0.05), absorption of L-rhamnose (P = 0.01) and 3-O-methyl-D-glucose was decreased (P = 0.003), and small bowel permeability was increased (P < 0.0001) in HIV-seropositive men compared with HIV-seronegative controls. HIV-seropositive subjects with a CD4 count less than 100 x 10(6)/l had decreased absorption of L-rhamnose (P < 0.05), D-xylose (P < 0.05) and 3-O-methyl-D glucose (P < 0.05) compared with HIV-seropositive subjects at higher CD4 counts, and had a similar resting energy expenditure to HIV-seronegative controls. Protein intake, carbohydrate, fat and protein oxidation. 24 h nitrogen excretion and appendicular muscle mass were similar in HIV-seropositive men and controls.

CONCLUSION

HIV infection exerts a direct effect on parameters of energy balance that varies with the severity of immunosuppression.

Mycobacterium kansasii: its presentation, treatment and outcome in HIV infected patients

AIM

To report the clinical significance and treatment of Mycobacterium kansasii infection in the context of HIV disease.

DESIGN/METHODS

Retrospective case review of all isolates of M kansasii until June 1994.

RESULTS

Ten cases of M kansasii were isolated. All but one patient with this infection had clinical symptoms compatible with generalised infection. The majority had chest infections with the organism isolated on induced sputum but not routine sputum. All isolates were sensitive to ethambutol and nine of 10 to rifampicin. All isolates were resistant to isoniazid and pyrazinamide.

CONCLUSION

M kansasii is a pathogen in HIV infected patients and should be treated when isolated. Treatment should be with rifampicin and ethambutol but not isoniazid, as has been recommended previously.

Pneumothorax in AIDS: case reviews and proposed clinical management

BACKGROUND

Pneumothorax is a not uncommon complication of advanced HIV infection, and may prove difficult to manage in view of its recalcitrant and recurrent nature. In this group where immunosuppression and reduced life expectancy are a feature, standard protocols are often abandoned in favour of a more conservative approach. This is often unsuccessful.

METHODS

Patients attending the Department of Genitourinary Medicine, Chelsea and Westminster Hospital who sustained pneumothorax between 1988 and 1992 were identified retrospectively and their notes reviewed.

RESULTS

Fifteen patients were identified of whom three had post-procedural pneumothoraces. In the remaining 12 patients, 10 had previously had Pneumocystic carinii pneumonia (PCP), whilst all 12 had some evidence to suggest current PCP (seven proven, five presumptive). In those six patients with a single, unilateral pneumothorax, four were managed successfully with intercostal drainage alone (one patient died early, one required pleurectomy). In those with recurrent pneumothoraces or pneumothoraces that did not respond to prolonged intercostal drainage, failure of medical treatment was judged to have occurred and surgery was performed. Overall, conservative management failed in 7/11 patients. Conversely surgery resulted in resolution in 7/7 with recurrence seen in one individual. Median survival was similar in the two groups.

CONCLUSIONS

Pneumothorax in patients with AIDS is associated with a high rate of intercurrent PCP; a low threshold for treating this infection presumptively is indicated. Intercostal drainage was successful in patients with a single, unilateral pneumothorax. However, in patients with recurrent or bilateral pneumothorax extended periods on intercostal drainage were uniformly unsuccessful. Early surgical referral should be considered in this group.

Faecal tumour necrosis factor-alpha in individuals with HIV-related diarrhoea

OBJECTIVE

HIV-related gastrointestinal infection is associated with diarrhoea, weight loss, mucosal inflammation and increased intestinal permeability. As tumour necrosis factor (TNF)-alpha may mediate these features this cytokine was measured in the faeces of HIV-seropositive individuals with diarrhoea to assess its role in the pathogenesis of HIV-related gastrointestinal disease and the association with specific intestinal pathogens.

DESIGN

Prospective study.

METHODS

Two hundred and four HIV-seropositive individuals provided stool samples that were analysed for faecal TNF-alpha (FTNF-alpha) using a standard sandwich enzyme-linked immunosorbent assay.

RESULTS

Stool from patients with bacterial, cytomegalovirus (CMV) and microsporidial diarrhoea had significantly elevated FTNF-alpha compared with those who had pathogen-negative diarrhoea (P < 0.05). FTNF-alpha was not raised in cryptosporidiosis, pathogen-negative or solid stool. In subjects with diarrhoea of more than 2 weeks duration and three stool samples negative for enteric pathogens, FTNF-alpha greater than 15 U/ml has a sensitivity of 88% and a specificity of 66% for the diagnosis of diarrhoea-related CMV enteritis.

CONCLUSION

TNF-alpha production may have a role in the pathogenesis of bacterial, microsporidial and CMV-related diarrhoea in HIV-seropositive individuals. Thus, anti-TNF-alpha agents may have a therapeutic role in the management of these conditions. FTNF-alpha greater than 15 U/ml in apparently pathogen-negative diarrhoea may suggest endoscopic gastrointestinal biopsy to diagnose CMV enteritis.

An efficient method for isolating putative promoters and 5'-transcribed sequences from large genomic clones

Efficient strategies to isolate promoters and flanking exons from large genomic clones would facilitate the assembly of transcription units, complement existing techniques to isolate expressed sequences, and provide 5' regulatory elements. We have developed a rapid and simple method to isolate promoters from large mammalian genomic DNA clones by exploiting the abundance of binding sites for the ubiquitous transcription factor Sp1 in gene promoters. Using this method, putative promoter sequences with Sp1-binding sites are enriched approximately 100-fold from fragmented P1 clone DNA. Based on the abundance of Sp1-binding motifs in promoters, we predict that a significant subset of vertebrate promoters could be isolated by this method.

Mainstream legitimization of homosexual men through Valentine's Day gift-giving and consumption rituals

Recently, the gay community has received increased attention from marketers through specially-made television commercials, direct mail pieces, and other media messages. However, little research in consumer behavior has examined the potential attitudinal and behavioral differences and similarities between heterosexuals and homosexuals. Specifically, this paper provides an exploratory look at the meaning and practices surrounding the consumer ritual of Valentine's Day from the perspective of homosexual men. Using depth interviews within an interpretative framework, our research suggests similarities exist for the celebration of Valentine's Day between homosexual and heterosexual singles, while differences may exist for the functions of Valentine's Day gift-giving between these groups. Some homosexual couples feel they cannot "legitimately participate" in the dominant rituals associated with the holiday due to oppression by a "heterosexual society". Marketing implications are discussed.

Intralesional interferon for the treatment of recalcitrant molluscum contagiosum in HIV antibody positive individuals--a preliminary report

Molluscum contagiosum is common in HIV disease and available therapies have a poor success rate and require frequent clinic visits. Interferon alpha has been used to treat recalcitrant condylomata acuminata and this study was undertaken to assess the use of this treatment in unresponsive molluscum contagiosum. A total of 30 molluscum contagiosum were injected with one megaunit of interferon alpha weekly for 4 weeks; 11 molluscum contagiosum completely cleared and 18 reduced in size by over 50%. Molluscum less than 0.5 cm in diameter, and those in patients without AIDS were more likely to respond. No surrounding lesions changed in size.

Comparison of the expression of native and mutant bovine annexin IV in Escherichia coli using four different expression systems

Bovine annexin IV, a Ca(2+)-dependent, membrane-binding protein, was expressed in E. coli using four different prokaryotic expression vector systems. An annexin IV cDNA was mutated in the 5' noncoding region to introduce an NcoI restriction site at the translation initiation site. The coding sequence was then excised and ligated into the expression vectors: pKK233-2 (which uses a hybrid trc promoter), pFOG405 (which uses the alkaline phosphatase promoter and generates a fusion protein with the alkaline phosphatase signal sequence that targets the protein for secretion), pOTSNco12 (which provides temperature-sensitive expression from the lambda phage promoter), and pET11d (which uses the T7lac promoter and a protease-deficient host). Expression of wild type and mutant annexin IV in the various systems was compared. Differences in level of expression, formation of inclusion bodies, and yield of purified protein were observed. The pET11d system was found to be the most effective expression system for annexin IV and various annexin IV mutant constructs, providing the highest yield of functional protein from the soluble fraction of cell lysates. Bovine chromaffin granule binding and aggregating activities of recombinant annexin IV were found to be virtually indistinguishable from those of bovine annexin IV isolated from liver tissue. Truncation constructs containing one, two, or three of the four conserved 70-amino-acid domains of native annexin IV were successfully created and expressed in E. coli, but the recombinant proteins were generally insoluble. pET11d annexin constructs containing point mutations in residues involved in binding calcium produced soluble protein at levels comparable to those of constructs expressing wild type protein.

Combinatorial mutagenesis of the four domains of annexin IV: effects on chromaffin granule binding and aggregating activities

This study addresses the roles of individual annexin IV domains in calcium-dependent membrane binding and aggregation through an analysis of the activities of mutant annexin IV proteins in which critical residues in one or more domains have been altered. The consensus sequence for high-affinity Ca(2+)-binding pockets obtained from the annexin V crystal structure is GXGT-38 residues-D/E [Huber, R., et al. (1992) J. Mol. Biol. 223, 683-704]. Site-directed mutagenesis was used to change the conserved acidic residues (D/E) in these sequences to alanine residues in each of the four domains of bovine annexin IV, singly or in combinations. Fourteen mutants with one, two, three, or four mutated domains were constructed and expressed in Escherichia coli. Purified recombinant product was evaluated for Ca(2+)-dependent binding to and aggregation of bovine chromaffin granules. Increases in the number of mutated domains resulted in increased Ca2+ requirements for both granule binding and aggregation. Further analysis revealed that mutations in individual domains had preferential effects on the binding or aggregating activities of the protein. For example, mutation of the first or fourth domains had a greater effect on membrane binding than aggregation, while conversely, mutation of the second domain had a more dramatic effect on membrane aggregation. Mutation of the third domain was largely silent in these assays. An additional mutation was made in the fourth domain to substitute a serine for a highly conserved arginine residue (Arg274) present at the C-terminus of the fourth endonexin fold. This mutation increased the calcium requirement for membrane binding 2-fold and for membrane aggregation 3-fold. This mutant protein was found to be an effective inhibitor of membrane aggregation by native annexin IV at intermediate levels of calcium.

Screening for lower genital tract infections in women presenting for termination of pregnancy

Over a four-month study period, 87 patients requesting termination of pregnancy at a gynaecology clinic were offered screening for sexually transmitted diseases, of whom 63 accepted. A total of 41 infections were found in 34 women, the commonest being vaginal candidiasis and bacterial vaginosis. Chlamydia was found in six patients. Although HIV antibody testing was offered to every patient, all declined this test.

The role of azoles in the treatment and prophylaxis of cryptococcal disease in HIV infection

OBJECTIVE

To assess the role of azole therapy in the treatment and prophylaxis of cryptococcosis in HIV-seropositive individuals.

STUDY DESIGN

Retrospective case review.

SETTING

A dedicated HIV unit in London, UK.

PATIENTS

Fifty individuals with a positive cryptococcal antigen or culture from any site between 1 January 1985 and 31 December 1992.

RESULTS

Thirty-eight patients initially presented with meningitis and 12 with alternative disease, five of whom subsequently developed meningeal disease. The 12 patients who presented without meningitis received chronic suppressive therapy after the diagnosis of cryptococcal disease. Two patients receiving itraconazole developed meningitis as did three out of four treated with 200 mg fluconazole daily, but none of the six receiving 400 mg fluconazole daily. Treatment of cryptococcal meningitis was successful in 17 of the 19 patients given fluconazole but only three of the six receiving itraconazole. Following successful treatment of meningitis five out of seven patients given itraconazole and five out of seven given 200 mg fluconazole daily relapsed compared with three out of 25 receiving 400 mg fluconazole daily.

CONCLUSION

Fluconazole is an effective treatment for cryptococcal meningitis. For prophylaxis following meningitis, a dose of 400 mg fluconazole is the preferred treatment; lower doses are associated with a higher relapse rate.

Congenital hip dislocation and pediatric hip disorders

The pediatric hip changes through development, leading to a challenging evaluation of pain. Common problems noted in children include congenital dislocation of the hip, Legg-Calve-Perthes disease, slipped capital femoral epiphysis, and transient synovitis. Hip disorders are also seen secondary to other childhood diseases, such as spina bifida. Long-term complications of all of these hip disorders can lead to joint deformity and osteoarthritis in adulthood.