A phase I study of the safety and tolerability of olaparib (AZD2281, KU0059436) and dacarbazine in patients with advanced solid tumours

Background:

Poly adenosine diphosphate (ADP)-ribose polymerase (PARP) is essential in cellular processing of DNA damage via the base excision repair pathway (BER). The PARP inhibition can be directly cytotoxic to tumour cells and augments the anti-tumour effects of DNA-damaging agents. This study evaluated the optimally tolerated dose of olaparib (4-(3--4-fluorophenyl) methyl-1(2H)-one; AZD2281, KU0059436), a potent PARP inhibitor, with dacarbazine and assessed safety, toxicity, clinical pharmacokinetics and efficacy of combination treatment.

Patients and methods:

Patients with advanced cancer received olaparib (20–200 mg PO) on days 1–7 with dacarbazine (600–800 mg m⁻² IV) on day 1 (cycle 2, day 2) of a 21-day cycle. An expansion cohort of chemonaive melanoma patients was treated at an optimally tolerated dose. The BER enzyme, methylpurine-DNA glycosylase and its substrate 7-methylguanine were quantified in peripheral blood mononuclear cells.

Results:

The optimal combination to proceed to phase II was defined as 100 mg bd olaparib with 600 mg m⁻² dacarbazine. Dose-limiting toxicities were neutropaenia and thrombocytopaenia. There were two partial responses, both in patients with melanoma.

Conclusion:

This study defined a tolerable dose of olaparib in combination with dacarbazine, but there were no responses in chemonaive melanoma patients, demonstrating no clinical advantage over single-agent dacarbazine at these doses.

Geographical information systems and tropical medicine

In terms of their applicability to the field of tropical medicine, geographical information systems (GIS) have developed enormously in the last two decades. This article reviews some of the pertinent and representative applications of GIS, including the use of such systems and remote sensing for the mapping of Chagas disease and human helminthiases, the use of GIS in vaccine trials, and the global applications of GIS for health-information management, disease epidemiology, and pandemic planning. The future use of GIS as a decision-making tool and some barriers to the widespread implementation of such systems in developing settings are also discussed.

Randomized clinical trial of routine on-table cholangiography during laparoscopic cholecystectomy

BACKGROUND

A randomized clinical trial was undertaken to assess the utility of routine on-table cholangiography (OTC) during laparoscopic cholecystectomy for gallstone disease.

METHODS

Some 190 patients with a history of biliary colic or cholecystitis and a low predictive risk for choledocholithiasis were randomized to undergo elective laparoscopic cholecystectomy alone (99 patients) or elective laparoscopic cholecystectomy with OTC (91). Intraoperative findings and postoperative outcomes for the two groups were compared. The primary outcome measure was the incidence of common bile duct (CBD) stones.

RESULTS

Of the patients undergoing OTC, ten had abnormal cholangiograms; three had CBD stones and seven had abnormalities without stones. OTC was associated with a significantly longer mean(s.e.m.) operating time (66(2) versus 54(3) min; P < 0·001), but there was no association between performance of OTC and postoperative morbidity. During a 1-year follow-up, no patient in the OTC group re-presented to hospital with recurrent biliary symptoms. In contrast, four of the patients allocated to surgery alone re-presented with symptoms suggestive of CBD obstruction; all settled with conservative treatment and the difference in readmission rate was not significant (P = 0·122).

CONCLUSION

Routine cholangiography in patients with a low risk for CBD stones does not seem justified from the results of this trial.

REGISTRATION NUMBER

NCT00806780 (http://www.clinicaltrials.gov).

Multiple sclerosis susceptibility alleles in African Americans

Multiple sclerosis (MS) is an autoimmune demyelinating disease characterized by complex genetics and multifaceted gene-environment interactions. Compared to whites, African Americans have a lower risk for developing MS, but African Americans with MS have a greater risk of disability. These differences between African Americans and whites may represent differences in genetic susceptibility and/or environmental factors. SNPs from 12 candidate genes have recently been identified and validated with MS risk in white populations. We performed a replication study using 918 cases and 656 unrelated controls to test whether these candidate genes are also associated with MS risk in African Americans. CD6, CLEC16a, EVI5, GPC5, and TYK2 contained SNPs that are associated with MS risk in the African American data set. EVI5 showed the strongest association outside the major histocompatibility complex (rs10735781, OR=1.233, 95% CI=1.06-1.43, P-value=0.006). In addition, RGS1 seems to affect age of onset whereas TNFRSF1A seems to be associated with disease progression. None of the tested variants showed results that were statistically inconsistent with the effects established in whites. The results are consistent with shared disease genetic mechanisms among individuals of European and African ancestry.

A phase II trial of lomeguatrib and temozolomide in metastatic colorectal cancer

To evaluate the tumour response to lomeguatrib and temozolomide (TMZ) administered for 5 consecutive days every 4 weeks in patients with metastatic colorectal carcinoma. Patients with stage IV metastatic colorectal carcinoma received lomeguatrib (40 mg) and TMZ (50–200 mg m⁻²) orally for 5 consecutive days every 4 weeks. Response was determined every two cycles. Pharmacokinetics of lomeguatrib and TMZ as well as their pharmacodynamic effects in peripheral blood mononuclear cells (PBMC) were determined. Nineteen patients received 49 cycles of treatments. Despite consistent depletion of O⁶-methylguanine-DNA methyltransferase in PBMC, none of the patients responded to treatment. Three patients had stable disease, one for the duration of the study, and no fall in carcinoembryonic antigen was observed in any patient. Median time to progression was 50 days. The commonest adverse effects were gastrointestinal and haematological and these were comparable to those of TMZ when given alone. This combination of lomeguatrib and TMZ is not efficacious in metastatic colorectal cancer. If further studies are to be performed, emerging data suggest that higher daily doses of lomeguatrib and a dosing period beyond that of TMZ should be evaluated.

Emergency intensive care admission following elective thoracic surgery

AIM

The aim of this study was to analyse the outcomes of patients admitted to the intensive care unit (ICU) following initial recovery after elective thoracic surgery.

METHODS

The case notes of all patients who underwent elective thoracic surgery over a one-year period were reviewed. Patients who were admitted to ICU following an initial recovery on the ward were identified and their postoperative course analysed. The clinical and demographic characteristics of these patients were recorded and their outcomes analysed.

RESULTS

A total of 20 patients were admitted to ICU of whom 13 (65%) were admitted for respiratory complication, 5 with sepsis and 2 with cardiovascular instability. Sixteen (80%) patients required CPAP or BIPAP, of whom only 7 (35%) required mechanical ventilation. Renal support was required in 7 patients, with 2 (10%) requiring haemofiltration. ICU survival was 15 patients (75%), whilst overall three-month survival post ICU admission was 65%. Requirement for renal support was the only predictor of mortality on univariate and multivariate analysis.

CONCLUSIONS

Salvage ICU admission following elective thoracic surgery is associated with significant mortality, however the outcome is far from hopeless. The majority of patients can be managed without recourse to mechanical ventilation or haemofiltration. The need for renal support is, however, a significant adverse prognostic indicator.

HIV-infected workers deported from the Gulf States: impact on Southern Pakistan

HIV prevalence is still very low in Pakistan, but its south Asian location and subgroups with recognized lifestyle risk factors suggest that Pakistan will experience expanded diffusion of HIV. We report the frequency of HIV infections identified by the AIDS Control Programme in the Sindh province of Pakistan. Most HIV positive cases currently reported to the Sindh AIDS Control Programme are found among Pakistani workers deported from the Gulf States and among foreigners. The 58 returned workers with HIV represent 61 to 86% of reported cases in any given year during the 1996-1998 period. Five wives of returning workers have been identified with HIV. Expatriate workers in the Gulf States are tested for HIV routinely, unlike other subgroups in Pakistan. Considering the risk of HIV/AIDS due to regular introduction of HIV from returned workers, and the limited awareness surrounding sexual health and HIV/STD transmission issues in Pakistan, intervention programmes targeted at overseas workers need to be implemented to control the expansion of the HIV epidemic in Pakistan (Int J STD AIDS 1999;10:812-14).

Pathological determinants of survival in node-negative oesophageal cancer

Background

Many studies have analysed prognostic factors following oesophagectomy, but few have examined survival determinants in node-negative (N0) oesophageal cancer. The prognostic significance of a number of histological variables following surgical resection of N0 oesophageal cancer was studied.

Methods

The case notes of 219 patients undergoing potentially curative oesophagectomy for N0 squamous cell carcinoma or adenocarcinoma of the oesophagus were reviewed. Details of the patient's sex, age at operation, histological type, longitudinal tumour length, tumour (T) stage, circumferential resection margin involvement, tumour grade, presence of vascular invasion, perineural invasion, Barrett's metaplasia, and survival were noted. Univariate and multivariate analyses were performed to identify prognostic factors.

Results

Univariate analysis revealed three factors that correlated with poor prognosis: T stage (P = 0·024), adenocarcinoma (P = 0·033) and degree of differentiation (P = 0·001). Multivariate analysis revealed that all three were significant independent adverse prognostic indicators.

Conclusion

Surgical resection of node-negative oesophageal cancer is associated with diverse long-term outcomes. This diversity of outcome is not reflected in the tumour node metastasis (TNM)-based staging system. The utility of the TNM system in predicting prognosis after surgical resection is open to question.

Experience with video-assisted surgery for suspected mediastinal tumours

AIM

To assess the therapeutic feasibility of video-assisted thoracoscopic surgery (VATS) in the excision of suspected mediastinal tumours.

METHODS

The case notes of 24 consecutive patients referred to a single surgeon between 1997 and 2002 for excision of suspected mediastinal tumours were reviewed. The operative, post-operative and pathological characteristics of patients treated thoracoscopically and by open procedure were analysed.

RESULTS

Thirteen of 24 patients underwent thoracoscopic excision. The mean age of the two groups was similar as was the mean operating time and duration of chest drainage. However, patients in the thoracoscopic group had less chest drainage, less pain and a shorter hospital stay.

CONCLUSIONS

Video-assisted thoracoscopic excision of mediastinal tumours is a safe and technically feasible procedure and may offer significant post-operative advantages over open procedures.

Cytomegalovirus disease following liver transplantation: an analysis of prophylaxis strategies

BACKGROUND

Cytomegalovirus (CMV) infection is an important cause of morbidity and mortality following liver transplantation. Though oral ganciclovir may be used as a prophylactic agent, there is some debate as to whether prophylaxis should be given universally or to targeted 'high risk' sub-groups. We, therefore, analysed the cost-effectiveness of both prophylactic strategies.

METHODS

We performed a retrospective cross-sectional study of adult liver transplant (LT) recipients who developed CMV disease in 1997 and estimated the morbidity and costs associated with disease in these patients. These costs were compared with the estimated cost (based on a previous multi-centre study) of using oral ganciclovir prophylaxis in order to assess the potential cost-effectiveness of introducing different prophylactic regimes.

RESULTS

Universal and targeted prophylaxis would both have prevented all the likely mortality (2 deaths) from CMV disease in that year. The net cost of applying a targeted prophylaxis strategy would have been 206,275 pounds, (i.e. 103,137 pounds per death avoided). The cost per life year saved would have been 15,674 pounds.

CONCLUSION

We suggest that LT units should identify patients at high risk for the development of CMV disease and adopt a targeted prophylactic strategy.

Prognostic significance of circumferential resection margin involvement following oesophagectomy for cancer

The factors affecting long-term survival following oesophagectomy for oesophageal cancer are poorly understood. We examined the significance of microscopic tumour involvement at the circumferential resection margin (CRM) on postoperative survival following oesophagectomy. The case notes of 329 patients who underwent a potentially curative oesophagectomy for squamous or adenocarcinoma were reviewed retrospectively. As part of the procedure, all patients underwent an en-bloc resection of their periesophageal tissue. The presence of tumour either at, or within, 1 mm of the CRM was recorded and correlated with their TNM and survival data. A total of 67 patients (20%) were noted to have a positive CRM, of which 40 cases (12%) had tumour at the resection margin and the remainder had tumour within 1 mm of the margin. Univariate analysis showed no statistically significant association between survival and either category of CRM involvement. Multivariate analysis showed that only T-stage, nodal status and tumour grade were prognostic markers. In conclusion, the presence of microscopic tumour at the CRM following an en-bloc oesophagectomy is not a significant prognostic marker.

Intercaudate nucleus ratio as a linear measure of brain atrophy in multiple sclerosis

Intercaudate nucleus ratio (ICR) is a linear measure of brain atrophy that does not require software application and is independent of image acquisition techniques. The authors examined the relationship between ICR and disability in 190 patients with MS. The results show that ICR correlates with Expanded Disability Status Scale score (r = 0.67; p = 0.0001) and disease duration (r = 0.32; p < 0.01). Intercaudate ratio appears to be a reliable and reproducible linear measure of brain atrophy and correlates with disability and disease duration in MS.

Methicillin-resistant Staphylococcus aureus incidence and outcome in patients with neck of femur fractures

Since the 1980s, methicillin-resistant Staphylococcus aureus (MRSA) has been identified as a significant infectious agent with an increasing incidence within both hospitals and the community. The aim of this study was to measure the incidence of MRSA colonization in patients admitted with a neck of femur fracture requiring implant surgery and to assess the outcome of these cases. We also sought to identify any risk factors associated with MRSA colonization, and to assess the need for any prophylactic treatment to prevent postoperative MRSA infection. Nasal, perineal and (where present) wound site swabs were taken on a sequential series of patients admitted with a neck of femur fracture who required a surgical implant. The presence of MRSA isolates from these swabs and the presence of a significant postoperative infection in both the colonized and non-colonized patients were recorded. A total of 66 patients were enrolled in the study, of whom 63 had surgical treatment for their fracture. A total of four patients were found to be colonized with MRSA. Of the study group, 27 patients had been admitted to hospital in the previous year, three of whom were found to be colonized with MRSA. Four of the patients were noted to have a postoperative infection-all of these cases were in the non-colonized group. The incidence of MRSA colonized patients in this series was 6%-a figure broadly consistent with previous studies. This does not appear to justify the routine screening of all neck of femur fracture admissions, though the results do suggest that a selective policy of screening only those who patients who had been admitted to hospital within the last year may be profitable. Our study does not appear to show any correlation between MRSA colonization and postoperative infection however. This is consistent with previous studies and does not support the adoption of an aggressive strategy for detection or eradication of MRSA prior to neck of femur fracture surgery.

Facial pain following sinonasal surgery or facial trauma

The case notes of 22 patients who reported facial pain after sinonasal surgery or trauma out of a cohort of 973 patients seen in a rhinology clinic were reviewed retrospectively. This group included 10 patients who had undergone endoscopic sinus surgery and four who had suffered facial fractures. None of the patients reported any facial pain before surgery or trauma. In only one case was there any evidence, clinically, endoscopically, or radiologically, of any paranasal sinus disease and when this resolved with nasal medical treatment the pain remained. The treatment of these patients' facial pain centred on the use of neurological medical treatment. One third of the patients responded to low-dose amitriptyline, a further third showed some response to other pharmacological agents including carbamazepine, and the remaining third showed no response. These cases illustrate the characteristics and management of facial pain after sinonasal surgery and highlight the importance of medical neurological treatment in the absence of any objective evidence of sinus disease.

A prospective, open-label treatment trial to compare the effect of IFNbeta-1a (Avonex), IFNbeta-1b (Betaseron), and glatiramer acetate (Copaxone) on the relapse rate in relapsing--remitting multiple sclerosis: results after 18 months of therapy

We previously reported results of a 12 month prospective, non-randomized, open-label treatment trial of immunomodulatory therapy in patients with relapsing-remitting multiple sclerosis (RRMS). We now report the results after 18 months of follow-up. Our primary objective was to compare the effect of IFNbeta-1a (Avonex), IFNbeta-1b (Betaseron), and Glatiramer Acetate (GA, Copaxone) to no treatment on the relapse rate in patients with RRMS. One hundred and fifty-six consecutive patients with clinically definite RRMS with a Kurtzke scale (EDSS) score of 4 or less were followed for 18 months. Prior 2-year relapse history and available chart information was carefully reviewed at the time of enrollment Thirty-three of 156 elected no treatment at enrollment; 40 elected IFNbeta-1a, 41 IFNbeta-1b, and 42 chose GA. There were no statistically significant differences among the four groups at enrollment. After 18 months of treatment 122 patients remained in their original treatment group. Compared to the untreated group (1.02), mean annualized number of relapses was significantly reduced only in the GA (0.49, P>0.0001) and IFNbeta-1b groups (0.55, P=0.001) in contrast to the IFNbeta-1a treated patients (0.81, P=0.106) who did not show a significant reduction. Despite limitations of the study design, the results provide helpful clinical information regarding the relative efficacy of each therapy in mildly affected treatment naive RRMS patients.

Responses to an emerging threat: HIV/AIDS policy in Pakistan

A decade has passed since the discovery of HIV in PAKISTAN: In the presence of a susceptible population, 'high-risk' behaviours and potential for further spread, the policies and programmes addressing HIV/AIDS need to be further developed. This paper explores the response to HIV/AIDS in Pakistan and describes the contributions of the public and private sectors towards AIDS prevention. A review of contextual and social factors of HIV/AIDS in Pakistan is followed by a structural analysis of the response, an assessment of the impact, and policy recommendations for a more integrated approach to this emerging threat. The conclusion calls for better epidemiological information on HIV/AIDS in the country, development of proactive, evidence-based policies, and socially appropriate implementation of prevention and care measures.

Effect of monthly intravenous cyclophosphamide in rapidly deteriorating multiple sclerosis patients resistant to conventional therapy

Fourteen consecutive clinically definite relapsing-remitting multiple sclerosis (MS) patients were treated with monthly intravenous cyclophosphomide (CTX) for 6 months. All had experienced severe dinical deterioration during the 12 months prior to treatment with CTX despite treatment with conventional immunomodulating agents and intravenous methylprednisolone. Treatment with CTX led to improvement and neurologic stability within 6 months which was sustained for at least 18 months after the onset of treatment with CTX. Therapy with CTX was well tolerated. CTX may be of benefit in MS patients who experience rapid clinical worsening and are resistant to conventional therapy.

A prospective, open-label treatment trial to compare the effect of IFN beta-1a (Avonex), IFNbeta-1b (Betaseron), and glatiramer acetate (Copaxone) on the relapse rate in relapsing-remitting multiple sclerosis

A prospective, non-randomized, open-label treatment trial was performed in patients with relapsing-remitting multiple sclerosis (RRMS), with follow up for 12 months. Our primary objective was to prospectively compare the effect of IFNbeta-1a (Avonex), IFNbeta-1b (Betaseron), and glatiramer acetate (GA, Copaxone) on the relapse rate in patients with RRMS. Between August 1996 and September 1999, 156 consecutive patients with clinically definite RRMS with a Kurtzke scale (EDSS) score of 4 or less were followed for 12 months, from the time of initiating therapy or electing to remain untreated. Prior 2-year relapse history and available chart information was carefully reviewed at the time of enrolment. Thirty-three of 156 elected no treatment (mean age 32.5 years; mean EDSS 2.64) at enrolment; 40 elected IFNbeta-1a (mean age 32.4 years; mean EDSS 2.69), 41 IFNbeta-1b (mean age 32.1 years; mean EDSS 2.56), and 42 chose GA (mean age 31.5 years; mean EDSS 2.57). Annual relapse rate based upon the 2 years prior to enrolment was 1.08 in the untreated group, 1.20 in the AV group, 1.21 in the BE group, and 1.10 in the GA group. There were no statistically significant differences among the four groups at enrolment. After 12 months of treatment, patients in the untreated groups had a relapse rate of 0.97, whereas patients in the IFNbeta-1a, IFNbeta-1b, and GA groups had relapse rate of 0.85, 0.61, and 0.62, respectively. Compared to the untreated group, reduction in the relapse rate was statistically significant only in the GA (P=0.003) and IFNbeta-1b (P=0.002) groups, in contrast to the IFNbeta-1a treated patients, who did not show a significant reduction (P=0.309). Compared to the untreated patients, mean EDSS was significantly reduced only in the GA (P=0.001) and IFNbeta-1b (P=0.01), in contrast to IFNbeta-1a treated patients (P=0.51). In this prospective, controlled, open-label, non-randomized 12-month study, treatment with only GA and IFNbeta-1b significantly reduced the relapse rate compared to untreated patients, supporting early treatment in RRMS. Our results are similar to the observations made after 12 months of therapy in phase III studies of IFNbeta-1a, IFNbeta-1b, and GA. Despite some limitations of the study design, the results provide helpful clinical information regarding the relative efficacy of each therapy in mildly affected treatment-naïve RRMS patients.

Anaesthesia and saccadic eye movements

During the last 10 years, there has been a vast increase in day-case surgery under general anaesthesia, but this has not been accompanied by research into the residual cognitive and motor effects during recovery from anaesthesia. Part of the explanation for this phenomenon is the lack of a suitable biophysical monitor of anaesthetic sedation. This review discusses one of the most commonly used of these biophysical monitors - namely saccadic eye movements. In particular, the efficacy of peak saccadic velocity as a monitor of sedation will be evaluated. In addition, the physiology and pharmacology of saccadic eye movements will be discussed within the context of developing other parameters of saccadic eye movements as novel biophysical monitors of anaesthetic sedation.

HIV-infected workers deported from the Gulf States: impact on Southern Pakistan

HIV prevalence is still very low in Pakistan, but its south Asian location and subgroups with recognized lifestyle risk factors suggest that Pakistan will experience expanded diffusion of HIV. We report the frequency of HIV infections identified by the AIDS Control Programme on the Sindh province of Pakistan. Most HIV-positive cases currently reported to the Sindh AIDS Control Programme are found among Pakistani workers deported from the Gulf States and among foreigners. The 58 returned workers with HIV represent 61 to 86% of reported cases in any given year during the 1996-1998 period. Five wives of returning workers have been identified with HIV. Expatriate workers in the Gulf States are tested for HIV routinely, unlike other subgroups in Pakistan. Considering the risk of HIV/AIDS due to regular introduction of HIV from returned workers, and the limited awareness surrounding sexual health and HIV/STD transmission issues in Pakistan, intervention programmes targeted at overseas workers need to be implemented to control the expansion of the HIV epidemic in Pakistan.

Sub-national response in HIV/AIDS: a case study in AIDS prevention and control from Sindh province, Pakistan

HIV/AIDS in Pakistan is slowly gaining recognition as a public health issue of great importance. However, the responses to the disease have been marred by lack of coordination and commitment. We examine, in this paper, the situation in the Sindh province of Pakistan, which is recognized as having the sole fully functioning AIDS prevention and control programme in the country. In discussing the results of the Sindh programme's activities we highlight progress made as well as gaps in data and surveillance. We also recommend strategies for implementation at the provincial and national levels. In addition this example of a sub-national government programme provides a case study for similar programmes in the region.

Neutralizing antibodies to interferon beta-1a and interferon beta-1b in MS patients are cross-reactive

OBJECTIVE

To determine whether neutralizing antibodies (NABs) to interferon beta (IFNbeta)-1a (Avonex) and IFNbeta-1b (Betaseron) cross-react.

BACKGROUND

A total of 38% of MS patients treated with IFNbeta-1b and 22% of those treated with IFNbeta-1a were reported to develop NABs, which could reduce the clinical efficacy of the drug.

METHODS

Blood from 10 MS patients was collected before and at 3 and 6 months after initiating treatment with IFNbeta-1a. ELISA was performed to detect binding antibodies to IFNbeta-1a. Sera from patients who tested positive for binding antibodies to IFNbeta-1a were then screened for NABs to IFNbeta-1a in a biologic assay based on neutralization of antiviral activity. These serum samples were subsequently tested for cross-reactivity with IFNbeta-1b both in the ELISA and the biologic assay. In the second part of the study, sera from patients who participated in the phase III IFNbeta-1b trial at the University of Maryland were examined for cross-reactivity with IFNbeta-1a in the ELISA and the biologic assay.

RESULTS

Of the 10 patients treated with IFNbeta-1a, three developed binding as well as NABs to IFNbeta-1a 6 months after treatment, and these antibodies cross-reacted with IFNbeta-1b both in the binding and the biologic assay. Similarly, sera from six patients with NABs to IFNbeta-1b showed cross-reactivity with IFNbeta-1a in the binding assay. Three of these six serum samples tested for neutralizing activity against IFNbeta-1a demonstrated the presence of NABs to IFNbeta-1a.

CONCLUSIONS

NABs to IFNbeta-1a (Avonex) and IFNbeta-1b (Betaseron) cross-react, both in the binding and the biologic assays. This suggests that switching to alternate IFNbeta preparation in patients who develop NABs may not be clinically beneficial. Studies examining cross-reactivity between NABs to IFNbeta-1a and IFNbeta-1b in a large number of patients are indicated.

HIV/AIDS in Pakistan: the context and magnitude of an emerging threat

STUDY OBJECTIVE

The objectives of this review were to: (1) assess the nature and comprehensiveness of information regarding HIV/AIDS in Pakistan; (2) to evaluate the extent of HIV/AIDS in Pakistan by epidemiological estimates; (3) to indicate the implications of the results for health policy in Pakistan and other regions at a similar stage in the epidemic.

DESIGN

A structured review of published, unpublished, and government literature was undertaken to collate all available information and present a descriptive epidemiological profile of HIV/AIDS in the country.

SETTING

Pakistan, a developing country in the South Asian region. National and regional information and analysis are presented in so far as the data allowed. Sample sizes varied from 1.35 million people screened at the national level to smaller studies of fewer than 100 screened.

RESULTS

Data pertaining to HIV/AIDS in Pakistan showed the best national estimates of HIV prevalence as 64 per 100,000 (0.064%). Within patients with sexually transmitted diseases the seroprevalence was as high as 6100 per 100,000 (6.1%); in men with extramarital contacts, 5400 per 100,000 (5.4%) and was as low as zero in some studied populations as well. The average age of onset was reported as 30 years. It is estimated that if all incident cases of AIDS were to die, there would be at least 5000 deaths annually attributable to HIV/AIDS.

CONCLUSION

Coupled with the extremely low awareness of HIV/AIDS in Pakistan, as well as growing number of cases, the AIDS epidemic is poised to take a hold in Pakistan. The presence of additional risk factors such as unscreened blood, and low condom use rates make the situation fertile for AIDS to become a major public health issue. Pakistan's health policy must be proactive in tackling this emerging health threat.

Serum interferon beta-1a (Avonex) levels following intramuscular injection in relapsing-remitting MS patients

BACKGROUND

The pharmacokinetics of IFNbeta-1a in MS patients are poorly understood. We have previously reported an ELISA sensitive and specific for measuring serum IFNbeta-1b levels in patients with MS.

OBJECTIVE

We describe an ELISA to measure interferon beta-1a (Avonex) in the serum of MS patients following IM administration.

METHODS

We have developed an ELISA for detecting serum IFNbeta-1a in MS patients receiving 6 million units (MU) of IFNbeta-1a, IM once weekly. The specificity of this ELISA was confirmed by the lack of cross-reactivity with other cytokines except for IFNbeta-1b.

RESULTS

Serum IFNbeta-1a levels were measured at 3 and 6 months after initiating treatment with IFNbeta-1a in 10 MS patients. At 3 months, all 10 patients had detectable levels ranging from 68 to 86 IU/mL. At 6 months, IFNbeta-1a could be detected in the serum of all but three patients, with levels ranging from 64 to 81 IU/mL. A kinetic study of IFNbeta-1a serum levels in a separate group of six MS patients who had been receiving IFNbeta-1a for several months was carried out. Blood was drawn before and 2, 4, 6, 8, and 24 hours after IFNbeta-1a injection. Peak serum IFNbeta-1a levels were observed at 8 hours and became undetectable at 24 hours after injection.

CONCLUSION

The described ELISA may have useful clinical applications in examining the correlation between serum IFNbeta-1a levels and clinical efficacy.

Effects of a low concentration of isoflurane on contrast sensitivity in volunteers

The effects of 0.15% quasi steady-state end-tidal isoflurane on the contrast sensitivity of five healthy volunteers were investigated by measuring their performance in computer generated letter discrimination tasks. A series of letters were displayed on a computer screen so that the luminance of the letter differed from that of the background. Two protocols were used: in the static protocol, the letter remained displayed on the screen until the subject responded, whereas in the dynamic protocol, the letter was displayed for 1/72 s only. Isoflurane significantly decreased contrast sensitivity in both protocols in all subjects.

Gabapentin relieves trigeminal neuralgia in multiple sclerosis patients

This report describes the effectiveness of gabapentin, a recently approved anticonvulsant, in seven patients with MS experiencing trigeminal neuralgia refractory to treatment with conventional medical therapy. Gabapentin relieved pain completely in six and significantly in the seventh patient. Gabapentin may be a valuable addition to pharmacologic therapy in trigeminal neuralgia, particularly in patients with MS and in refractory cases.

Incidence of exacerbations in the first 90 days of treatment with recombinant human interferon beta-1b in patients with relapsing-remitting multiple sclerosis

Interferon beta-1b (IFNbeta-1b) is effective in reducing the frequency of exacerbations in patients with relapsing-remitting multiple sclerosis (RRMS). Recently, a study suggested that treatment with IFNbeta-1b may place MS patients at risk of exacerbations by increasing interferon-gamma (IFNgamma)-secreting cells in the blood early after onset of treatment. We conducted a retrospective study in 192 RRMS patients treated with IFNbeta-1b. We did not observe an increase in the frequency of exacerbations early after the onset of treatment and suggest that the IFNgamma-secreting cell surge linked to the onset of treatment with IFNbeta-1b may not be clinically significant.

Immunomodulating functions of recombinant ovine interferon tau: potential for therapy in multiple sclerosis and autoimmune disorders

The interferons (IFN) are a family of complex proteins possessing antiviral, antiproliferative, and immunomodulatory activities. Two type I recombinant human IFN have been recently approved for the treatment of multiple sclerosis (MS). However, use of high dose type I IFN treatment in MS patients has been limited by dose-related toxicity. Ovine IFN tau is a unique type I interferon discovered for its role in the animal reproductive cycle. It differs from other type I IFNs in that it is remarkably less toxic even at high concentrations, is able to cross species barriers, and is not inducible by viral infection. Ovine IFN tau has been shown to be very effective in the treatment of animal models of MS. In this study, we examined the toxicity of OvIFN tau on human T-cells at high doses and its immunregulatory properties at equivalent doses. Our experiments confirmed the remarkably non-toxic nature of OvIFN tau on human cells at high concentrations as well as immunomodulating properties consistent with other type I IFNs including an antilymphoproliferative effect and inhibition of IFN gamma-induced HLA class II expression. These results suggest that OvIFN tau could be developed into a potentially less toxic therapeutic option for immune-mediated disorders including MS.

Antibodies to the axolemma-enriched fraction in the cerebrospinal fluid and serum of patients with multiple sclerosis and other neurological diseases

Antibodies to an axolemma-enriched fraction (AEF) antigen have been detected in the cerebrospinal fluid (CSF) and serum of patients with Multiple Sclerosis (MS) using an enzyme-linked immunosorbent assay (ELISA). A marginal elevation (P < 0.08) of anti-AEF IgG was found in MS CSF when compared with OND samples. When CSF was diluted to a standardized IgG concentration, the anti-AEF IgG level in MS CSF was significantly elevated (P=0.007) when compared to OND CSF. MS serum was also found to contain a significantly higher level (P < 0.001) of anti-AEF IgG when compared to OND serum using the ELISA technique.

Concurrence of multiple sclerosis and brain tumor: clinical considerations

We report a patient with multiple sclerosis (MS) who developed an oligodendroglioma 8 years after the initial diagnosis of MS. This is the first description of a neoplasm, suspected initially on brain MRI and subsequently confirmed by brain biopsy, in an MS patient. Our case emphasizes the need to evaluate atypical brain MRI lesions carefully, even in well-established MS patients, as well as to obtain a tissue diagnosis of such lesions whenever possible in order to determine their precise etiology.

Treatment with oral 3,4 diaminopyridine improves leg strength in multiple sclerosis patients: results of a randomized, double-blind, placebo-controlled, crossover trial

To examine the efficacy and toxicity of oral 3,4 diaminopyridine (DAP) in dosages up to 100 mg/day, 36 patients with multiple sclerosis (MS) enrolled in a randomized, double-blind, placebo-controlled, crossover trial. The primary outcome measure was improvement of a prospectively defined neurologic deficit, which was leg weakness in 34 patients. Secondary outcome measures included the patient's subjective response, scored manual motor testing (MMT) of leg strength, scored leg strength from videotaped motor testing (VMT), quadriceps and hamstrings strength (QMT) measured by isometric dynamometry, neuropsychological testing (NPT), ambulation index (AI), and Expanded Disability Status Scale (EDSS) score. Paresthesias and abdominal pain were common and were dose limiting in eight patients. Three patients had episodes of confusion, and one patient had a seizure while on DAP. Eight patients withdrew from the study, leaving 28 evaluable patients for the efficacy analysis. The prospectively defined neurologic deficit improved in 24 patients-22 on DAP and 2 on placebo (p = 0.0005). All improvements were in leg weakness. Subjective response and measures of leg strength and function (MMT, VMT, QMT, and AI) improved on DAP compared with placebo. Neither NPT nor EDSS scores improved. DAP treatment can induce improvements in leg strength in MS patients, but toxicity is limiting in many patients.

Interferon beta-1b serum levels in multiple sclerosis patients following subcutaneous administration

Recombinant interferon beta-1b (rIFNbeta) reduces the frequency of exacerbations in relapsing-remitting MS when administered subcutaneously on alternate days. However, the pharmacokinetics of rIFNbeta are not well understood and there are scant data on the detectability of rIFNbeta in the serum of MS patients following subcutaneous administration. Moreover, existing assays for detecting IFNbeta are biologic, time-consuming, and require handling of infectious agents. We developed and standardized an ELISA specific for measuring rIFNbeta with a detection range of 40 to 1,000 IU/ml. The specificity of our ELISA was confirmed by the lack of cross-reactivity with other cytokines, including IFNalpha, IFNgamma, IFN Consensus-1, and TNFalpha. We screened serum from 34 MS patients drawn within 12-36 hours of treatment: 15 patients taking 8 MIU, four patients taking 1.6 MIU, and 15 patients taking placebo. Eleven of the 15 patients in the 8-MIU treatment group had measurable rIFNbeta serum levels ranging from 120 to 475 MIU/ml. Two of four patients in the 1.6-MIU treatment group, but none of the placebo group, had detectable serum rIFNbeta levels. A small prospective time-course study was carried out in four MS patients receiving rIFNbeta. Serial blood samples were obtained prior to and 4, 8, 24, and 48 hours after rIFNbeta injection. A peak serum rIFNbeta level was observed between 8 and 24 hours after rIFNbeta injection and tended to decline to near preinjection levels at 48 hours postinjection. These results are consistent with the rationale of alternate-day, subcutaneous administration of rIFN beta. In addition, the ELISA described might be a useful tool to study the pharmacokinetics and the relationship of rIFN beta serum levels to clinical efficacy.

Multiple sclerosis: a review of existing therapy and future prospects

Multiple sclerosis (MS) is an incurable neurological illness that frequently causes chronic disability. Neurologists broach the diagnosis with dread. "I'll end up in a wheel chair" is the anguished cry of the newly diagnosed and mostly young patients. The past decade has improved our understanding of the immunopathogenesis of MS enormously. This has led to a plethora of clinical trials and the resultant emergence of several new drugs in various stages of development. In 1993, Food and Drug Administration (FDA) approved Betaseron for the treatment of MS. Todate, this is the only drug approved by the FDA, specifically for the treatment of MS. However, it would not be too long before several other drugs are approved, leaving the neurologist bewildered having gone from a state of practically little to offer to a state of several options to choose from. This review discusses the status of current and future therapy in the treatment of MS. Multiple sclerosis (MS) is the most common demyelinating disease of the human central nervous system (CNS). Medline includes over 13000 articles on MS since 1966 that exclude book chapters and other references. MS typically affects the youth and women more than men, between the ages of twenty and forty. Clinically, the illness is characterized into a relapsing-remitting (RR) or chronic progressive (CP) stage although more precisely defined stages exist for research purposes. It tends to follow a highly unpredictable course leading to chronic and sometimes devastating disability. More recently, follow up data suggested that the disease may fall into a pattern after several years. Despite decades of hectic research and better understanding of immunological mechanisms involving human CNS disease, the cause of MS remains unknown. However, it is widely believed that MS is the result of an autoimmune disorder in a genetically susceptible individual, mediated by autoreactive T cells that migrate into the CNS and initiate the inflammatory demyelinating lesion. Regardless of the plausibility of this theory and without going into details, several aspects of immune mediated pathology of MS remain unexplained. This is an attempt to review the status of current therapy and future prospects in the treatment of MS.

Visually induced paroxysmal nausea and vomiting as presenting manifestations of multiple sclerosis

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Myasthenia gravis presenting as dysphagia: clinical considerations

Myasthenia gravis is an autoimmune disorder of the neuromuscular junction that causes muscle weakness. Involvement of oropharyngeal musculature is not uncommon, which leads to dysphagia. Timely consideration of myasthenia gravis in evaluating dysphagia is crucial to prevent complications and to improve the quality of life of these patients. We report four patients who underwent extensive investigations for dysphagia, by gastroenterologists as well as otolaryngologists, before the diagnosis of myasthenia gravis was established.