Outcome of uncorrected CSF leak and consequent recurrent meningitis in a patient: a case presentation and literature review

Purpose: Post-traumatic CSF leaks are a complication in 2% of all head injuries. Majority of these patients will recover spontaneously. Whilst recent literature has predominantly centred on CSF leaks and their general investigations and management thereof, there is a paucity of information when it comes to those patients who have persistent post-traumatic CSF leaks, as well as the complication of recurrent meningitis. We present a patient with a persistent post-traumatic CSF leak who presented with recurrent bacterial meningitis thirteen times- the highest documented amount in an adult. We reviewed the literature with regards to the above as well.Material and Methods: We reviewed a vast array of journal articles on the topic of CSF leaks from the PubMed resource, and focused this review specifically on those that documented patients who had uncorrected CSF leaks and their outcomes.Results: Complications include meningitis and rhinorrhoea with brain abscesses and pneumocephalus occurring less frequently. Mortality has been documented to be 9% after 1 year. The rates of persistent CSF leaks were within the same range with an average calculated rate of 21%. Whilst meningitis was recorded and is common, it was not stipulated whether the incidences were recurrent.Conclusion: Post-traumatic persistent CSF leaks remain a therapeutic challenge and continued follow-up with early surgical intervention is highly recommended to prevent complications. One of the more serious complications of a persistent leak is meningitis. The long-term outcomes of recurrent meningitis could include cumulative focal neurological deficitis and cognitive impairment.

Reduced risk of toxoplasma encephalitis in HIV-infected patients – a prospective study from Gauteng, South Africa

Toxoplasma seroprevalence was determined in 307 consecutive HIV-infected medical inpatients at the Helen Joseph Hospital, Johannesburg, South Africa, using an enzyme linked immunosorbent assay to detect immunoglobulin G (IgG) and IgM antibodies. The mean age of patients was 36 years, with a female to male ratio of 1.3 to 1. The mean CD4 count was 109 cells/mL. Toxoplasma antibodies were detected in 25 patients (8%). Twenty-two of these patients were IgG positive and IgM negative, i.e. reactivation toxoplasmosis. Only two patients (0.65%) had clinical manifestations of toxoplasmosis (one toxoplasma encephalitis and one retinitis). The risk for toxoplasma encephalitis (TE) was 0.33%. These results indicate that the toxoplasma seroprevalence and the TE risk in this population is low. The implication from this study is that in HIV-infected populations where the toxoplasma seroprevalence is low, the TE risk will be low and empiric treatment of focal brain lesions with anti-toxoplasma therapy may be inappropriate.

Relationship between the neuroprotective effects of insulin-like growth factor-1 and 17β-oestradiol in human neuroblasts

Insulin-like growth factor-1 (IGF-1) and oestrogens interact with each other as neuroprotective factors. We have previously demonstrated that 17β-oestradiol protects against β-amyloid and oxidative stress toxicity and increases the amount of cell cholesterol in human foetal neuroblasts (FNC). The present study aimed: (i) to assess the protective effects of IGF-1 in FNC cells; (ii) to investigate the relationship between IGF-1 and 17β-oestradiol; and (iii) to determine whether cholesterol was a major mediator of the effects of IGF-1, similarly to 17β-oestradiol. We found that IGF-1 effectively exerts neuroprotective effects in FNC cells. We also demonstrated that the IGF-1 receptor (IGF-1R) pathway is needed to maintain oestrogen-mediated neuroprotection. Finally, we found that, opposite to 17β-oestradiol, IGF-1 did not cause a significant increase in cell cholesterol. These findings indicate that a cross-talk between IGF-1 and 17β-oestradiol occurs in FNC cells. In particular, the activation of the IGF-1R cascade appears to be fundamental to warrant 17β-oestradiol-mediated neuroprotection, even though cell cholesterol does not play a major role as an effector of this pathway.

Non-traumatic myelopathy at the Chris Hani Baragwanath Hospital, South Africa--the influence of HIV

BACKGROUND

Non-traumatic myelopathy from developing regions has been described widely. In these regions infections, mainly tuberculosis, followed by acute transverse myelitis and neoplasms, dominate. These are also regions of high HIV prevalence. In developed regions, the most prominent reported spinal cord disease in HIV/AIDS is vacuolar myelopathy (VM). Other myelopathy causes in HIV/AIDS include opportunistic infections, neoplasms, vascular lesions and metabolic disease. In developing regions, opportunistic infections are more commonly encountered with VM occurring less frequently.

AIM

To determine the influence of HIV on the myelopathy spectrum in an HIV endemic region.

DESIGN

Prospective case series.

METHODS

Hundred unselected consecutive in-patients admitted with myelopathy were studied. Myelopathy aetiologies were established by collating information obtained from magnetic resonance imaging (MRI) scans, CSF and blood studies, CXR findings, non-neurological illness and response to treatment. Data were analysed in terms of two cohorts, HIV positive and HIV negative.

RESULTS

Approximately 50% of the patients presenting and admitted to our hospital with non-traumatic myelopathy are HIV positive. The HIV positive myelopathy patients were younger (20-40 years) and had infectious aetiologies. Tuberculosis was the most frequently identified cause of myelopathy. The majority of HIV-positive patients had advanced HIV infection. Anti-retroviral treatment did not influence myelopathy aetiologies. The HIV-negative patients were older and had neoplasms, followed by degenerative spondylosis as the main myelopathy causes.

CONCLUSION

HIV influences the non-traumatic myelopathy spectrum in regions with high HIV prevalence. Empiric treatment of HIV-myelopathy patients with anti-tuberculous medications where resources are severely limited has merit.

Human immunodeficiency virus associated intracranial aneurysms: report of three adult patients with an overview of the literature

BACKGROUND AND PURPOSE

Aneurysms have been described in HIV infected patients. These involve predominantly extracranial blood vessels with specific histological and clinical features. Intracranial aneurysms are rare and have been identified mainly in children.

METHODS

Case reports and literature review.

RESULTS

Three black South African HIV positive adult patients with intracranial aneurysms were identified. The clinical, laboratory and radiological features are described.

CONCLUSIONS

Intracranial aneurysms occur in both adults and children infected with HIV. More information is required on this association. The frequency in terms of numbers of cases indicates that it is an uncommon association or manifestation of HIV. The characteristics of the aneurysms suggest that they are distinctive and not a chance or coincidental co-occurrence of congenital or arteriosclerotic aneurysms.

Blood pressure-measuring devices in rural South Africa: an audit conducted by the SASPI team in the Agincourt field site

BACKGROUND

Cardiovascular disease is an important cause of morbidity and mortality in South Africa. The Southern Africa Stroke Prevention Initiative (SASPI) found a high prevalence of stroke in the rural Agincourt subdistrict, Limpopo province. Hypertension is the commonest vascular risk factor in our population and it is essential that primary care services be adequately equipped to detect and treat hypertension. The aim of this study was to assess the number, accuracy and working condition of blood pressure measuring devices (BMD) in the clinics that serve the field site, and to assess the clinic sisters' perceptions of the availability of antihypertensive medication and aspirin.

METHODS

In each of the clinics serving the site we assessed the BMDs and cuffs using the following criteria: general condition, bladder size, state of rubber components, operation of the inlet valve and control of valve operation. The legibility of the gauge, level and condition of the mercury, and the condition of the glass tube were checked when relevant. The performance of the BMD was then assessed both with the cuff used in the clinic and with a new functioning cuff, against an accurate mercury sphygmomanometer. By interviewing the clinic sister we could assess the availability of antihypertensive medication and aspirin, as well as the state of the drug delivery system.

RESULTS

All BMDs were mercury sphygmomanometers. Four clinics had one BMD each, one clinic had two, and one clinic had four. In one clinic the device was not functional at all until the study cuff was used. None of the clinics had spare cuffs and only one clinic had access to a large cuff. Nine out of 10 (90%) cuffs tested had unsatisfactory valve function, and none was of the size recommended by the guidelines. Although the condition of the mercury was only considered satisfactory in 40% of BMDs, once a new cuff had been fitted to the BMDs all of them were accurate to within 4 mmHg between 50 and 250 mmHg. Fifty per cent of clinic sisters felt they always had sufficient stock of hydrochlorothiazide and alpha-methyldopa, but the supply of more expensive medication was less reliable. Only one clinic always had sufficient aspirin.

CONCLUSION

Although none of the primary care clinics had fully functioning BMDs, almost all the defects related to malfunctioning and inappropriately sized cuffs, which would be inexpensive to repair or replace. A procedure for routine servicing or replacement of both BMDs and cuffs is needed, as well as optimisation of medication delivery to remote areas.

Protein S deficiency in HIV associated ischaemic stroke: an epiphenomenon of HIV infection

The purpose of the study was to determine the relevance of protein S deficiency in HIV infected patients with ischaemic stroke. In total, 33 HIV positive patients with ischaemic stroke, previously described by us, were prospectively compared with control groups for occurrence of protein S deficiency. The control groups comprised an equal number of consecutive matched HIV positive and negative patients without and with stroke respectively. Data were analysed in contingency tables using Fisher's exact test. Protein S deficiency occurred significantly more frequently in HIV positive compared with HIV negative stroke patients (p < 0.001). However, by including HIV positive patients without stroke as a control group and comparing this group with the HIV positive stroke group we found that protein S deficiency is statistically related to HIV infection and not stroke occurrence. Our data indicate that the presence of protein S deficiency in HIV positive patients with stroke is an epiphenomenon of HIV infection.

Management of HIV-associated focal brain lesions in developing countries

BACKGROUND

HIV-associated focal brain lesions (HFBL) are caused by opportunistic infections, neoplasms, or cerebrovascular diseases. In developed countries, toxoplasma encephalitis (TE) is the most frequent cause, followed by primary CNS lymphoma (PCNSL). Guidelines based on these causes however are poorly suited to developing countries, where treatable infections predominate as causes of HFBL.

AIM

To determine a practical approach to the management of HFBL in developing countries.

DESIGN

Case series.

METHODS

Patients (n = 32) were managed based on presumed aetiologies of the focal brain lesions, determined by collating information from CT scans, CSF and blood studies, concurrent non-neurological illness and response to treatment.

RESULTS

The principal presumed cause of HFBL was tuberculosis (69%). The therapeutic response was good in 69% of patients.

DISCUSSION

In developing countries, infections are the predominant cause of HFBL, the principal causes being infections that are endemic to the populations being studied. Empiric treatment based on limited investigations should be directed according to the nature of such infections. A modified algorithm is proposed.

Hepatitis C virus related cryoglobulinemic glomerulonephritis

A 46 years male presented with skin rash and acute nephritic syndrome. He had history of jaundice four months back. Rheumatoid factor and cryoglobulins were present in the serum. Although anti-HCV antibodies were negative, HCV RNA was detected by polymerase chain reaction. Kidney biopsy showed membranoproliferative glomerulonephritis and thrombi in the lumen of the glomerular capillary loops. His renal functions improved with steroids.

Effects of lithium chloride on induction and expression of methylphenidate sensitization

Repeated administration of psychomotor stimulants produces an enduring and progressively enhanced behavioral response known as behavioral sensitization, which has been implicated as a model for psychiatric disorders such as mania, schizophrenia, and drug addiction. The objective of the study was to determine whether lithium chloride (LiCl), an anti-manic agent, is effective in blocking the development and/or the expression of behavioral sensitization to methylphenidate. Male Sprague-Dawley rats (n=64) weighing 170-190 g were randomly divided into seven treatment groups. A computerized animal activity monitor system continuously recorded locomotor activity for 16 days. Effects of LiCl on induction of methylphenidate sensitization were studied by giving LiCl before or during six daily methylphenidate administrations. Effects of LiCl on the expression of methylphenidate sensitization were studied by injecting LiCl after sensitization to methylphenidate was induced. It was shown that LiCl treatment modulated the acute methylphenidate effects by transiently attenuating the locomotor response to methylphenidate during the six daily methylphenidate administrations but neither single nor multiple treatments with LiCl blocked the development or the expression of behavioral sensitization.

Optic neuritis in an urban black African community

PURPOSE

To describe the clinical profile of idiopathic optic neuritis in South African blacks.

METHODS

South African black patients with acute isolated idiopathic optic neuritis, treated and followed for at least 3 months at a large medical centre, were studied. Exclusion criteria were other causes of optic neuropathy (such as ischaemic optic neuropathy, toxins or Leber's hereditary optic neuropathy); all causes of optic neuritis (such as HIV, neurosyphilis, sarcoid or connective tissue disease); neurological disease outside of the optic nerves; and any race other than South African black. Patients underwent extensive ophthalmic, neurological, radiological, cerebrospinal fluid and blood assessment.

RESULTS

Eighteen eyes of 10 patients were studied. The mean age was 35.7 years and 9 patients were female. Only 2 patients had truly unilateral optic neuritis, the other 8 having either bilaterally simultaneous or consecutive disease. Presenting visual acuity (VA) was less than 6/60 in 17 of 18 eyes, with severe dyschromatopsia in all eyes. Fifteen eyes had optic disc swelling. All patients were treated with corticosteroids. After at least 3 months follow-up only 6 eyes recovered VA of 6/12 or better, with only 3 eyes recovering colour vision of 10/13 or better on Ishihara plate testing. No patient had multiple sclerosis (MS) on presentation, nor developed MS on follow-up.

CONCLUSION

Idiopathic optic neuritis in black South Africans differs from that in whites. The higher prevalence of bilateral cases and of optic disc swelling, the weaker association with MS and the extremely poor visual outcome distinguish optic neuritis in black South Africans.

The salivary adenosine/AMP content of Phlebotomus argentipes Annandale and Brunetti, the main vector of human kala-azar

Adenosine and AMP in the salivary glands of the sand fly Phlebotomus argentipes were characterized by reversed-phase high-pressure liquid chromatography with diode-array detection and mass spectrometry. AMP and adenosine were measured in individual salivary gland pairs, yielding 76.8 +/- 8.6 and 380 +/- 25 pmoles per pair of salivary glands, respectively (mean +/- SE, n = 12). These values decrease to 45 +/- 7 and 181 +/- 21 pmoles following a blood meal, indicating that AMP and adenosine were secreted. Because adenosine and AMP have anti-platelet, vasodilatory, and immunomodulatory properties, it is proposed that these salivary nucleotides help the fly to blood feed and may affect Leishmania transmission.

Demyelinating disorder of the central nervous system occurring in black South Africans

OBJECTIVES

To investigate the nature and cause in eight black South African patients of a recurrent (multiphasic), remitting, and relapsing demyelinating disease of the CNS.

METHODS

The clinical and laboratory investigations and radiological manifestations of these patients were documented.

RESULTS

Each patient had two or more acute attacks of demyelinating disease affecting the CNS. The clinical presentations of the patients were predominantly those of multiphasic neuromyelitis optica (NMO). Brain MRI in these patients showed features consistent with those described for acute disseminated encephalomyelitis (ADEM), as well as lesions that are described in multiple sclerosis. There was involvement of the corpus callosum in addition to typical ADEM lesions. Laboratory investigations excluded all other known causes of multiphasic CNS demyelination. Oligoclonal antibodies were not detected in these patients at any time. The patients were all from a population with a low risk for MS (black South Africans).

CONCLUSION

The patients described here represent a new phenotypic expression of a recurrent (multiphasic), steroid sensitive, inflammatory demyelinating disorder of the CNS occurring in black South Africans. The disorder is either a distinct inflammatory demyelinating disorder of the CNS of as yet unknown aetiology, or a varied form of MS (ADEM/NMO) occurring in a population with a low risk (where the genetic trait and environmental risk factors for MS do not exist) for MS.

New-onset seizures associated with HIV infection

The authors studied new-onset seizures in 60 heterosexual black South African HIV-infected patients who had not used IV drugs. An intracranial space-occupying lesion was identified in 53% of patients, meningitis in 22%, and no additional cause in 25%. Of the patients with an identifiable cause, 64% had probable tuberculosis (tuberculoma or tuberculous meningitis). The majority of patients had late-stage HIV infection (CD4 counts <200/mm(3)).

Protection against cutaneous leishmaniasis resulting from bites of uninfected sand flies

Despite the fact that Leishmania are transmitted exclusively by sand flies, none of the experimental models of leishmaniasis have established infection via sand fly bites. Here we describe a reproducible murine model of Leishmania major infection transmitted by Phlebotomus papatasi. Prior exposure of mice to bites of uninfected sand flies conferred powerful protection against Leishmania major that was associated with a strong delayed-type hypersensitivity response and with interferon-gamma production at the site of parasite delivery. These results have important implications for the epidemiology of cutaneous leishmaniasis and suggest a vaccination strategy against this and possibly other vector-borne diseases.

Case reports: postpartum cerebral angiopathy in a patient with chronic migraine with aura

A 25-year-old woman with a history of chronic severe migraine with aura presented in an apoplectic state 1 week after the delivery of her third child. She developed a severe headache and within hours lapsed into a coma. A CT scan of the brain showed cerebral edema and an occipital hemorrhage. A four-vessel angiogram showed diffuse arterial narrowing of all the intracranial vessels with segmental narrowing of the suprasellar portion of the internal carotid arteries bilaterally. She had no risk factors for stroke or vasculitis. Her pregnancy and delivery were uneventful with no preeclampsia or eclampsia. Apart from ergometrine at the time of the delivery, no vasoconstrictor drugs were used. She recovered spontaneously. Serial CT scans of the brain demonstrated resolution of the edema and hemorrhage with the development of cortical and watershed infarcts. A repeat cerebral angiogram was normal. She was, therefore, diagnosed as having suffered from postpartum cerebral angiopathy, a form of reversible cerebral vasoconstriction, called the Call or Call-Fleming syndrome. The relationship between migraine and postpartum angiopathy in the development of reversible cerebral vasoconstriction is discussed.

Evolution of lesion formation, parasitic load, immune response, and reservoir potential in C57BL/6 mice following high- and low-dose challenge with Leishmania major

A model of cutaneous leishmaniasis using 10(2) Leishmania major metacyclic promastigotes inoculated into the footpads of genetically resistant C57BL/6 mice was studied in order to more accurately reproduce the evolution of lesion formation and the kinetics of parasite growth and immune response as they might occur in naturally exposed reservoirs and in human hosts. In contrast to the more conventional experimental model employing 10(6) metacyclic promastigotes, in which the rapid development of footpad lesions was associated with an increasing number of amastigotes in the site, the low-dose model revealed a remarkably "silent" phase of parasite growth, lasting approximately 6 weeks, during which peak parasitic loads were established in the absence of any overt pathology. Footpad swelling was observed after 6 weeks, coincident with the onset of parasite clearance and with production of high levels of interleukin-12 (IL-12) and gamma interferon (IFN-gamma) in draining lymph nodes. Low-dose challenge of IL-12- and IFN-gamma-depleted or -deficient mice provided strong evidence that the induction or expression of cellular immunity is essentially absent during the first 6 to 8 weeks of intracellular growth, since the concentration of amastigotes in the site was not enhanced compared to that for wild-type animals during this time. By monitoring the ability of infected mice to transmit parasites to vector sand flies, it was observed that following low-dose challenge, footpads without apparent lesions provided an efficient source of parasites for exposed flies and that the low-dose challenge actually extended the duration of parasite transmissibility during the course of infection.

Cores in hypothyroid myopathy: a clinical, histological and immunofluorescence study

Fifteen patients with primary hypothyroidism were evaluated neurologically. Needle biopsies of skeletal muscle were obtained using a Bergstrom needle. In 73% of the patients, cores were identified histologically and by electron microscopy in the skeletal muscle of these patients. The presence of cores correlated with the severity of hypothyroidism, muscle hypertrophy, cramps and the duration of the hypothyroid state. There was no significant correlation with muscle weakness. Immunofluorescence studies with N-CAM antibodies demonstrated staining of the sarcolemma, cytoplasm and central regions (cores) in the hypothyroid muscle. These imply that the presence of cores in hypothyroid myopathy is due to reactivation of embryonic proteins that disrupt skeletal muscle architecture.

The clinical and genetic characteristics of spinocerebellar ataxia type 7 (SCA 7) in three Black South African families

OBJECTIVES

Spinocerebellar ataxia type 7 is a rare autosomal dominant neurodegenerative disorder characterized by progressive cerebellar and retinal degeneration, described in various population groups in the literature. This is the first description from South Africa. The objective was to document the clinical and genetic characteristics of our patients and to determine concordance with other described cases.

PATIENTS AND METHODS

The index cases were identified clinically on the basis of the typically described features of progressive ataxia with visual failure due to progressive cerebellar and retinal/macular degeneration. Associated neurological disturbances were documented. Where possible, and available, family members were assessed and pedigrees were delineated. Molecular tests for SCA expansions were determined in the index cases.

RESULTS

Three pedigrees of SCA 7 were identified. The patients were all Black South Africans. The genetic and clinical characteristics are typical for SCA 7.

CONCLUSION

SCA 7 is a rare distinct neurodegenerative disorder characterized by trinucleotide expansion.

The role of phosphoglycans in Leishmania-sand fly interactions

Leishmania promastigotes synthesize an abundance of phosphoglycans, either attached to the cell surface through phosphatidylinositol anchors (lipophosphoglycan, LPG) or secreted as protein-containing glycoconjugates. These phosphoglycans are thought to promote the survival of the parasite within both its vertebrate and invertebrate hosts. The relative contributions of different phosphoglycan-containing molecules in Leishmania-sand fly interactions were tested by using mutants specifically deficient in either total phosphoglycans or LPG alone. Leishmania donovani promastigotes deficient in both LPG and protein-linked phosphoglycans because of loss of LPG2 (encoding the Golgi GDP-Man transporter) failed to survive the hydrolytic environment within the early blood-fed midgut. In contrast, L. donovani and Leishmania major mutants deficient solely in LPG expression because of loss of LPG1 (involved in biosynthesis of the core oligosaccharide LPG domain) had only a slight reduction in the survival and growth of promastigotes within the early blood-fed midgut. The ability of the LPG1-deficient promastigotes to persist in the midgut after blood meal excretion was completely lost, and this defect was correlated with their inability to bind to midgut epithelial cells in vitro. For both mutants, when phosphoglycan expression was restored to wild-type levels by reintroduction of LPG1 or LPG2 (as appropriate), then the wild-type phenotype was also restored. We conclude, first, that LPG is not essential for survival in the early blood-fed midgut but, along with other secreted phosphoglycan-containing glycoconjugates, can protect promastigotes from the digestive enzymes in the gut and, second, that LPG is required to mediate midgut attachment and to maintain infection in the fly during excretion of the digested blood meal.

Total dose iron infusion: safety and efficacy in predialysis patients

Iron deficiency anemia is not uncommon in predialysis patients. Oral iron often cannot maintain adequate iron stores. Hence we evaluated the safety and efficacy of total dose infusion (TDI) of iron in these patients. Anemic predialysis patients were screened and those with Hb < 7.0 g/dL and serum ferritin < 200 ng/mL were selected. Patients with active bleeding and acute liver disease were excluded. All patients were on oral iron 100 mg/day. None of the patients were on erythropoeitin. 11 patients (6 males and 5 females), aged 45.9 +/- 15 yrs, were suitable. Hb was 5.9 +/- 1.0 g/dL and serum ferritin was 89.5 + 50 ng/mL. The preparation used was iron dextran. A test dose of 25 mg in 100 mL normal saline was administered over 1 hr to all patients. One patient had fever and chills during the test dose and was not given TDI. 10 patients received TDI. None of these patients had any problem during the infusion. The dose of iron administered was 900 + 316.2 mg. One patient who received 1600 mg had arthralgia-myalgia and another patient had thrombophlebitis following TDI. One month after TDI, Hb was 8.0 + 1.0 g/dL and serum ferritin was 362 ng/mL. We feel that TDI is a safe and effective method of correcting iron deficiency in predialysis patients.

Intra-species and stage-specific polymorphisms in lipophosphoglycan structure control Leishmania donovani-sand fly interactions

The Leishmania lipophosphoglycan conveys the ability for the parasites to avoid destruction in diverse host environments. During its life cycle within the sand fly vector, the parasite differentiates from a dividing procyclic promastigote stage that avoids expulsion from the midgut by attaching to the gut wall, to a nondividing metacyclic promastigote stage that is unable to attach to the midgut and migrates to the mouth parts for reinfection of a mammalian host. Lipophosphoglycan plays an integral role during this transition. Structurally, lipophosphoglycan is a multidomain glycoconjugate whose polymorphisms among species lie in the backbone Gal(beta 1,4)Man(alpha 1)-PO(4) repeating units and the oligosaccharide cap. We have characterized the lipophosphoglycan from an Indian L. donovani isolate. Unlike East African isolates, which express unsubstituted repeats and a galactose- and mannose-terminating cap, procyclic lipophosphoglycan from the Indian isolate consists of beta1,3-linked glucose residues that branch off the backbone repeats (n approximately 17) and also terminate the cap. Of biological significance, metacyclic lipophosphoglycan lacks the glucose residues while doubling the number of repeats. The importance of these developmental modifications in lipophosphoglycan structure was determined using binding experiments to Phlebotomus argentipes midguts. Procyclic promastigotes and procyclic LPG were able to bind to sand fly midguts in vitro whereas metacyclic parasites and LPG lost this capacity. These results demonstrate that the Leishmania adapts the synthesis of terminally exposed sugars of its LPG to manipulate parasite-sand fly interactions.

Development of a natural model of cutaneous leishmaniasis: powerful effects of vector saliva and saliva preexposure on the long-term outcome of Leishmania major infection in the mouse ear dermis

We have developed a model of cutaneous leishmaniasis due to Leishmania major that seeks to mimic the natural conditions of infection. 1,000 metacyclic promastigotes were coinoculated with a salivary gland sonicate (SGS) obtained from a natural vector, Phlebotomus papatasii, into the ear dermis of naive mice or of mice preexposed to SGS. The studies reveal a dramatic exacerbating effect of SGS on lesion development in the dermal site, and a complete abrogation of this effect in mice preexposed to salivary components. In both BALB/c and C57Bl/6 (B/6) mice, the dermal lesions appeared earlier, were more destructive, and contained greater numbers of parasites after infection in the presence of SGS. Furthermore, coinoculation of SGS converted B/6 mice into a nonhealing phenotype. No effect of SGS was seen in either IL-4- deficient or in SCID mice. Disease exacerbation in both BALB/c and B/6 mice was associated with an early (6 h) increase in the frequency of epidermal cells producing type 2 cytokines. SGS did not elicit type 2 cytokines in the epidermis of mice previously injected with SGS. These mice made antisaliva antibodies that were able to neutralize the ability of SGS to enhance infection and to elicit IL-4 and IL-5 responses in the epidermis. These results are the first to suggest that for individuals at risk of vector-borne infections, history of exposure to vector saliva might influence the outcome of exposure to transmitted parasites.

Targeted gene deletion of Leishmania major genes encoding developmental stage-specific leishmanolysin (GP63)

The major surface glycoprotein of Leishmania major is a zinc metalloproteinase of 63 kDa referred to as leishmanolysin or GP63, which is encoded by a family of seven genes. Targeted gene replacement was used to delete gp63 genes 1-6 encoding the highly expressed promastigote and constitutively expressed GP63. In the L. major homozygous mutants deficient in gp63 genes 1-6, there was no expression of GP63 as detected by reverse transcription-polymerase chain reaction (RT-PCR) or fluorescent staining in promastigotes from the procyclic stage (logarithmic growth phase). The remaining L. major gP63 gene 7 was shown to be developmentally regulated, as it was expressed exclusively in infectious metacyclic stage (late stationary growth phase) promastigotes and in lesion amastigotes. The gp63 genes 1-6-deficient mutants showed increased sensitivity to complement-mediated lysis. The sensitivity to lysis was greater in procyclics than in metacyclics when compared with the equivalent wild-type stages. Increased resistance of the mutant metacyclic promastigotes correlated with the expression of gp63 gene 7 and was restored to the same levels as wild-type promastigotes by transfection with gp63 gene 1. Thus, expression of GP63 is clearly involved in conferring resistance to complement-mediated lysis. The L. major GP63 1-6 mutants were capable of infecting mouse macrophages and differentiating into amastigotes. Similar levels of infection and subsequent intracellular survival were observed when mouse macrophages were infected in vitro with wild type, GP63 1-6 mutants and mutants transfected with gp63 gene 1. The GP63 1-6 mutants were capable of lesion formation in BALB/c mice and, thus, gp63 genes 1-6 do not play a role in the survival of the parasite within mouse macrophages. The role of gp63 genes 1-6 in parasite development within the sandfly vector was studied. GP63 1-6 mutants grew normally in the blood-engorged midgut of both Phlebotomus argentipes and P. papatasi However, both wild-type and mutant promastigotes were lost after 2 days' growth in P. papatasi. The complete developmental pathway in P. argentipes was observed for wild-type promastigotes, GP63 1-6 mutants and mutants transfected with gp63 gene 1. Normal stage differentiation from amastigotes to procyclics, to nectomonads, to haptomonads and to infectious metacyclics was observed. Thus, the highly expressed promastigote forms of GP63, encoded by gp63 genes 1-6, do not appear to be required for nutrient utilization in the bloodmeal during the early stages of development in the sandfly or for midgut attachment and further development. gp63 1-6 genes do, however, play a major protective role against complement-mediated lysis when promastigotes are introduced into the mammalian host.

The clinicoradiological profile of cerebral venous thrombosis

The clinical presentation, diagnostic and radiological aspects and the probable aetiology in 20 consecutively studied patients with cerebral venous thrombosis (CVT) are described. In this retrospective analysis patients were evaluated extensively according to a stroke investigative protocol. Computed tomography signs for CVT may be identified in the majority of cases and frequently obviate the need for angiography. In those patients in whom no satisfactory precipitating factor was recognised further haematological tests revealed abnormalities that are known causes of thrombosis in 7 patients. Eighty-five per cent of the patients made an excellent recovery. It is concluded that CVT can often be diagnosed non-invasively, the presumptive cause can be found in the majority of patients and the prognosis is excellent.

Vitelliform macular degeneration associated with mitochondrial myopathy

A patient with mitochondrial myopathy is described. Examination of his fundus revealed bilateral vitelliform degeneration of the maculae. This lesion is a focal abnormality of the retinal pigment epithelium and may be a manifestation of the underlying mitochondrial disease.

Predictive estimation of sandfly biting density at a focus of cutaneous leishmaniasis in the North Sinai Desert, Egypt

Human-landing rates were compared with CDC light trap and oiled paper sticky trap rates to evaluate efficacy for estimating human-biting density of Phlebotomus papatasi. Strong correlation coefficients of 0.83 and 0.93 were obtained for monthly sticky trap rates and CDC light trap rates, respectively, against the monthly means for sandfly landing rate/man/hour suggesting that both methods could provide a reliable alternative method for estimating and predicting human-biting density.

Immunological evidence for the co-existence of the Lambert-Eaton myasthenic syndrome and myasthenia gravis in two patients

Two patients are described in whom a clinical and electromyographic diagnosis of the Lambert-Eaton myasthenic syndrome (LEMS) was made. Serum antibodies to voltage-gated calcium channels (VGCCs), the antigenic target in LEMS and to acetylcholine receptors (AChRs), the antigen in myasthenia gravis, were detected at raised titres in both cases, using radioimmunoassays based on 125I-omega-Conotoxin labelled VGCCs and 125I-alpha-Bungarotoxin labelled AChRs. These data provide immunological evidence for the coexistence of the two disorders in these patients.

Spinal cord schistosomiasis. A clinical, laboratory and radiological study, with a note on therapeutic aspects

Fourteen patients with schistosomiasis of the spinal cord are described. They fall into two groups: 7 patients had clinical and computer-assisted myelographic evidence of lesions in the conus medullaris or cauda equina, or both. The clinical picture in the remaining 7 patients was usually that of acute or subacute transverse myelitis with normal or equivocal CT myelographic appearances. Granulomas containing bilharzial ova were found in 2 female patients with conus swelling subjected to laminectomy and biopsy. In 1 of these the ova were identified as S. haematobium while in the second, unidentified bilharzial ova were found. A presumptive diagnosis of spinal cord schistosomiasis was made in the remaining 12 patients based on characteristic clinical and investigative profiles. All 13 patients tested showed evidence of bilharzial infection based on positive blood serology or the detection of bilharzial ova, or both. All but 1 patient showed at least one of the following abnormalities on CSF examination: pleocytosis, an elevated protein content and as indicated by the presence of oligoclonal IgG bands, an elevated IgG index and an increased CSF IgG synthesis rate. A CSF bilharzia enzyme-linked immunosorbent assay (ELISA) test, developed to indicate the presence of schistosomal infection within the theca, was found to be sensitive although not entirely specific for the diagnosis of spinal cord schistosomiasis. Eleven of the 14 patients showed rapid clinical improvement, 8 after praziquantel and corticosteroid treatment, 2 after operation and 1 spontaneously. Significant reductions in the CSF cell count, protein concentration and bilharzia ELISA titre, and in intrathecal antibody production, occurred following praziquantel and corticosteroid therapy. The CSF sugar level showed a significant rise. A reduction in conus size was observed in 3 patients when CT myelography was repeated after medical therapy. The normalization of most of the laboratory parameters after combined medical treatment with praziquantel and corticosteroids, together with clinical and radiological improvement, strengthened the presumptive diagnosis of cord schistosomiasis and supports the policy of early intensive medical treatment (as opposed to surgical therapy) for this condition when diagnosed on indirect evidence.

Myelopathy associated with human T cell lymphotropic virus type I (HTLV-I) in natal, South Africa. A clinical and investigative study in 24 patients

Unexplained spastic myelopathy in black (Zulu) patients, similar to that seen in the tropics, has previously been described from Natal, South Africa. Following reports linking the human T cell lymphotropic virus type I (HTLV-I) to spastic myelopathy, we undertook a prospective and retrospective search for HTLV-I antibodies in 36 patients who were labelled as having unexplained myelopathy; 24 (66%) were positive and HTLV-I was isolated from 4 out of the 6 patients whose peripheral blood lymphocytes were cultured. Eighteen (75%) gave a short history (less than 6 months). There was a female preponderance (71%), spinothalamic dysfunction was common (55%) and as many as half were severely disabled (50% wheelchair bound). Routine laboratory studies showed no specific trends apart from hypergammaglobulinaemia and CSF pleocytosis (greater than 5 cells/microliter in 66% of patients). The total CSF protein was raised (greater than 0.4 g/l) in 45% of patients. The IgG index was greater than 0.7 in 15 of 19 patients. Conventional myelography did not show any specific abnormalities. Computer assisted myelography was undertaken in 22 patients; 3 showed arachnoiditis and 2 spinal cord atrophy. Periventricular lucencies were seen in 1 of 10 patients who had computed tomography of the head. Nerve conduction studies demonstrated abnormalities in 46% of the patients indicating that subclinical peripheral nerve dysfunction was common. Visual evoked responses were abnormal in only 1 patient but brainstem auditory evoked response studies showed some abnormality in 42% of the patients. The finding of HTLV-I antibodies in a significant number, and the isolation of HTLV-I from the blood in 6 of our black patients with noncompressive myelopathy, represents a substantial clinical advance. Future studies should define more clearly the role of the virus in this disorder.

Subacute sclerosing panencephalitis. Changes on CT scan during acute relapse

A 19-year-old female patient presented in an acute state of akinetic mutism. Serological analysis of serum and cerebrospinal fluid demonstrated the presence of antibodies to measles virus. CT scan carried out during this acute phase of relapse demonstrated white matter enhancement affecting the cortical white matter of the frontal lobes and corpus callosum. These features indicate that active demyelination occurs during acute relapse in subacute sclerosing panencephalitis (SSPE) and suggest that immunotherapy should be considered during this acute phase.

A muscle-type tropomyosin in human fibroblasts: evidence for expression by an alternative RNA splicing mechanism

We have isolated a cDNA clone from a human fibroblast cDNA library that contains the entire protein-coding region of a 1.1-kilobase mRNA. This mRNA encodes a 284-amino acid tropomyosin, the primary structure of which most closely resembles smooth muscle tropomyosin. Thus, the expression of both 284-amino acid muscle-type and 247-amino acid non-muscle-type tropomyosins appears to be a normal feature of human non-muscle cells. We also present evidence to suggest that this cytoskeletal tropomyosin and a human skeletal muscle beta-tropomyosin are derived from a common structural gene by an alternative RNA splicing mechanism.

Heparin with low affinity to antithrombin III inhibits the activation of prothrombin in normal plasma

Standard unfractionated heparin is known to have two actions on blood clotting. Unfractionated heparin enhances the rates at which antithrombin III inactivates activated clotting factors, and inhibits the activation of both Factor X and prothrombin by disrupting the calcium and phospholipid dependent assembly of the Factor X and prothrombin activator complexes. This latter inhibitory action of heparin occurs independently of antithrombin III. A heparin fraction with low affinity to antithrombin III was prepared from standard heparin by affinity chromatography on antithrombin-III-Sepharose and its properties compared with unfractionated heparin. The low affinity heparin fraction and the unfractionated heparin had equivalent inhibitory effects on prothrombin activation in antithrombin III depleted plasma. In normal plasma, the low affinity fraction inhibited the activation of prothrombin. Unlike the unfractionated heparin, however, the fraction of heparin with low affinity to antithrombin III did not enhance the inactivation of either Factor Xa or thrombin. This antithrombin III independent inhibition of the activation of prothrombin was also evident when activated platelets were used as the source of the procoagulant phospholipids. The antithrombin III independent effect of heparin is unlikely to be important therapeutically, however, if this property of heparin is shared by other naturally occurring glycosaminoglycans, it could be important in maintaining the fluidity of blood under physiological conditions.