The induction of angiogenesis by the implantation of autologous bone marrow cells: a novel and simple therapeutic method

BACKGROUND

Bone marrow contains many kinds of primitive cells that could differentiate to endothelial cells and secrete several growth factors. In the current study, we attempted to induce therapeutic angiogenesis by implanting autologous bone marrow cells (BMCs) and using a rat ischemic hind limb model.

METHODS

BMCs were prepared by removing red blood cells. A rat ischemic hind limb model was made by the ligation of the left femoral artery and its branches. BMCs were injected into 7 points of the ischemic muscles. To assess angiogenesis, a microangiogram, laser Doppler, and histologic evaluation were performed after the surgical procedure.

RESULTS

A microangiogram and histologic evaluation showed that angiogenesis was significantly induced in the ischemic hind limb by the implantation of BMCs. Laser Doppler imaging analysis showed that blood flow was significantly increased after implantation of BMCs. Some implanted BMCs were stained positively with CD31 and vascular endothelial-cadherin (VE-cadherin), which might have been incorporated into the vasculature. The condition of ischemia caused an elevation in the level of basic fibroblast growth factor in the ischemic muscle and also in interleukin-1beta derived from the implanted BMCs, which might contribute to angiogenesis.

CONCLUSION

These findings indicate that autologous bone marrow implantation may be a novel and simple method for inducing therapeutic angiogenesis.

Determinants of continuous positive airway pressure compliance in a group of Chinese patients with obstructive sleep apnea

OBJECTIVE

To assess continuous positive airway pressure (CPAP) compliance and factors associated with CPAP compliance among Chinese patients with obstructive sleep apnea (OSA).

DESIGN

A prospective study of 112 consecutive patients with newly diagnosed OSA commencing CPAP treatment.

SETTING

A university teaching hospital.

MEASUREMENTS AND RESULTS

The following factors were evaluated for any correlation with objective CPAP compliance (effective mask pressure [hours per day]) at 1 month and 3 months: age, baseline apnea-hypopnea index (AHI), common OSA symptoms, minimum arterial oxygen saturation (SaO(2)), mean SaO(2), arousal index (AI), Epworth sleepiness scale (ESS), education level, CPAP levels, satisfaction with CPAP, side effects, and machine cost. There were 101 male and 11 female patients, with a mean (+/- SD) age of 45.6 +/- 1.2 years; body mass index, 29.3 +/- 5.2 kg/m(2); AI, 60 +/- 18/h; AHI, 48 +/- 24/h; minimum SaO(2) of 70 +/- 17%; and mean SaO(2) of 86 +/- 7%. ESS fell from 12.9 +/- 4.0 (baseline) to 5.2 +/- 4.7 at 3 months (p < 0.001). Objective CPAP compliance was 5.4 +/- 1.6 h/d and 5.3 +/- 1.6 h/d, while 75% and 72% of our patients were using CPAP objectively for > or = 4 h/d and at least 70% of the nights per week at 1 month and 3 months, respectively. Following univariate analysis of variance, a high baseline AHI (p = 0.006 and p = 0.004) was associated with higher objective CPAP compliance at 1 month and 3 months, respectively.

CONCLUSION

CPAP usage and compliance were high in this patient population. A high baseline AHI was the only significant independent predictor of better CPAP compliance.

Synthesis of ethyl alkylidene alpha cyanoacetates under ultrasound irradiation

Condensation of ketones with ethyl cyanoacetate catalysed by ammonium acetate-acetic acid results in ethyl alkylidene alpha cyanoacetate in 31-89% yield under ultrasound irradiation.

Autologous bone marrow implantation induced angiogenesis and improved deteriorated exercise capacity in a rat ischemic hindlimb model

BACKGROUND

Bone marrow possesses endothelial progenitor cells that secrete several growth factors and can contribute to the formation of new capillaries. In the present study, we investigated the extent of angiogenesis induced by implantation of autologous bone marrow cells (BMCs) in a rat ischemic hindlimb model and studied whether the increased collateral vessels can improve deteriorated physical function.

MATERIALS AND METHODS

Ischemic hindlimb was created by ligation of the femoral artery and its branches in Dark Agouti (DA) rats. BMCs (1 x 10(7)) were injected percutaneously at six points into the gastrocnemius muscle. To assess angiogenesis, histologic evaluation and microangiography were performed at 2 weeks postligation. Severity of the ischemic insult was evaluated by measuring blood flow in the adductor and gastrocnemius muscles using nonradioactive colored microspheres and by determining the femoral arteriovenous oxygen difference (AVDO(2)) at 2 weeks postligation. Running time on a motor-driven treadmill was used to represent exercise capacity.

RESULTS

The histologic evaluation and microangiogram showed that the implanted BMCs induce angiogenesis. Blood flow to the adductor muscle on the treated side in the bone marrow cell implantation (BMI) group was significantly restored to 77.3 +/- 19.3% of that of the normally perfused limb in comparison to that in control groups (P < 0.05). AVDO(2) in the BMI group significantly decreased when compared with AVDO(2) in control groups. Rats in the BMI group ran approximately 1.5 times longer than rats in control groups at 2 and 4 weeks postligation (P < 0.01).

CONCLUSIONS

Implantation of autologous BMCs induced angiogenesis and improved deteriorated exercise capacity in our rat ischemic hindlimb model.

Increasing drug concentration in a rat lung tumor model by combining isolated lung perfusion with hypertensive chemotherapy

Isolated left lung perfusion (ILP) with cisplatin was performed in Fisher 344 rats. Before perfusion, bolus injection with endothelin was given via the pulmonary artery. The vasoconstrictive potency was estimated by monitoring the perfusion pressure. The toxicity was estimated by tracking body weight change, survival rate after right pneumonectomy, arterial blood gas analysis and histological findings. To observe the pharmacokinetic changes, a solitary Methylcholanthrene-induced sarcoma model was established in a rat lung and the total platinum concentration in perfused lung and tumor tissues was measured. Perfusion pressure was increased significantly in a dose-dependent manner. Pulmonary toxicity from ILP with cisplatin was limited by the use of endothelin. Significantly higher levels of total platinum were obtained in tumors but not in normal lung tissues by endothelin injection before ILP than by ILP alone. The combination of ILP and hypertensive chemotherapy should be one of the available treatments for unresectable pulmonary carcinoma.

Digitonin enhances the anti-tumor effect of cisplatin against methylcholanthrene-induced rat sarcoma cells in vitro

BACKGROUND

This study was designed to evaluate cellular uptake and cytotoxicity of cisplatin in methylcholanthrene (MCA)-induced rat sarcoma cells when used in combination with a detergent, digitonin.

MATERIALS AND METHODS

In the cellular intake study, after MCA sarcoma cells (10(7)) were treated with cisplatin alone (50 micrograms/ml) and with cisplatin (50 micrograms/ml) in combination with digitonin at 20 microM and 50 microM, the cells were washed twice with PBS and the platinum levels were measured by flameless atomic spectrometry. For the anti-tumor effect MCA sarcoma cells (10(3)) were seeded in cell culture dishes and loaded for 10 minutes with PBS, digitonin (5 microM), cisplatin (5 micrograms/ml) or a combination of cisplatin (5 micrograms/ml) and digitonin (5 microM). The cells were then washed and incubated for 72 hours. Bromodeoxyuridine uptake was measured with an ELISA system for determining viable cells counts.

RESULTS

Cell platinum levels were significantly elevated in proportion to the increase of digitonin (p < 0.0001). The number of viable cells was significantly decreased with, the combined cisplatin (5 micrograms/ml)--digitonin (5 microM) treatment (p < 0.0001

CONCLUSION

Digitonin enhances the antitumor effect of cisplatin against methylcholanthrene-induced rat sarcoma in vitro.

EMG responses in humans during painful heterosegmentary stimulation

The amplitude-temporal parameters of the nociceptive flexor reflex evoked in the upper and lower extremities by painful heterosegmentary electrical stimulation were studied in healthy volunteers. This reflex was detected bilaterally in the muscles of the upper and lower extremities independently of the site of painful stimulation. The maximum amplitude of the reflex was observed in the case, when the segmentary muscle innervation and the application site of painful stimulation coincided. The least latency of the nociceptive flexor reflex was observed after painful stimulation of the ear lobe. It was concluded that nociceptive flexor reflex is not an elementary polysynaptic spinal reaction, but involves also some supraspinal centers.

Relationship between the concentration of CDDP in tumor and tumor size after isolated lung perfusion treatment experimental study on a solitary pulmonary sarcoma model in rats

BACKGROUND AND OBJECTIVES

Few investigations on the pharmacokinetics of isolated lung perfusion (ILP) regional chemotherapy in tumors have been conducted. The purpose of this study was to evaluate the pharmacokinetic character of ILP in tumor tissues. Materials and Methods A solitary tumor nodule model was established in Fisher 344 rats by inoculating 1.0 x 10(6) methylcholanthrene-induced sarcoma cells into the left lung. On 14-21 days after the inoculation of tumor cells, rats were randomized into groups subjected to 10, 20, 40 or 60 min ILP with cis-diamminedichloroplatinum (CDDP) at concentrations of 25, 50, or 100 microg/ml. Total platinum concentration in tumors was measured by a flameless atomic absorption spectrophotometer.

RESULTS

The average tumor weights and total platinum concentrations were not significantly different among the perfusion groups. We found, however, that the total platinum concentrations in tumor nodules were significantly correlated inversely with the tumor weight (total platinum concentration in tumor = 1.167 x 1/tumor wt; R(2) = 0.981; P < 0.001).

CONCLUSIONS

The concentration of total platinum in the tumor tissue was found to be dependent on the weight of the tumor in ILP. Higher concentrations of total platinum were expressed in smaller tumor nodules than larger ones, indicating that ILP may be more effective against small tumors than large ones. Therefore, we suggest that large tumor legions should be debulked before ILP in patients with an unresectable lung tumor.

Prevalence of sleep disturbances in chinese patients with end-stage renal failure on continuous ambulatory peritoneal dialysis

Patients with end-stage renal failure (ESRF) are reported to have a high prevalence of sleep disorders, such as daytime sleepiness, insomnia, restless legs syndrome (RLS), and obstructive sleep apnea syndrome (OSAS). However, there are few published data from Southeast Asia. A sleep questionnaire was administered to 201 patients (103 men) at the continuous ambulatory peritoneal dialysis (CAPD) outpatient clinic to assess sleep problems. Patients had a mean age of 56.7 +/- 12 (SD) years, with a mean body mass index (BMI) of 23.6 +/- 3.5 kg/m(2). Daytime sleepiness was the most frequent symptom (77.1%), and frequent awakening occurred in 69% of the patients. Sleep-onset insomnia and sleep-maintenance insomnia occurred in 73% and 60% of the patients, respectively. Sixty-two percent of the patients reported symptoms of RLS, which significantly correlated with sleep-onset insomnia (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.5 to 5.5; P = 0.001) and sleep-maintenance insomnia (OR, 2.1; 95% CI, 1.2 to 3.8; P = 0.014). The prevalence of OSAS was estimated by the frequency of the following symptoms: extremely loud snoring, 7 patients (3.5%); observed choking, 21 patients (10.5%); witnessed apnea, 11 patients (5.6%); snoring and witnessed apnea, 6 patients (3%); disruptive snoring, 29 patients (14.4%); and disruptive snoring and witnessed apnea, 3 patients (1.5%). This questionnaire survey confirmed a high prevalence of daytime sleepiness, insomnia, and RLS in patients with ESRF undergoing CAPD but showed a relatively low prevalence of OSAS of up to 14.4%, which may be related to the low BMI of these patients with ESRF compared with other populations. Whether this contributes to the overall better survival observed in some Asian patients with ESRF undergoing dialysis needs further investigation.

Dynamics of HIV-specific CD8+ T lymphocytes with changes in viral load.The RESTIM and COMET Study Groups

The influence of HIV burden variations on the frequencies of Ag-specific CD8+ T cell responses was evaluated before and during highly active antiretroviral therapy by analyzing the number, diversity, and function of these cells. The frequencies of HLA-A2-restricted CD8+ PBL binding HLA-A2/HIV-epitope tetramers or producing IFN-gamma were below 1%. A panel of 16 CTL epitopes covering 15 HLA class I molecules in 14 patients allowed us to test 3.8 epitopes/patient and to detect 2.2 +/- 1.8 HIV epitope-specific CD8+ subsets per patient with a median frequency of 0.24% (0.11-4. 79%). During the first month of treatment, viral load rapidly decreased and frequencies of HIV-specific CD8 PBL tripled, eight new HIV specificities appeared of 11 undetectable at entry, while CMV-specific CD8+ PBL also appeared. With efficient HIV load control, all HIV specificities decayed involving a reduction of the CD8+CD27+CD11ahigh HIV-specific effector subset. Virus rebounds triggered by scheduled drug interruptions or transient therapeutic failures induced four patterns of epitope-specific CD8+ lymphocyte dynamics, i.e., peaks or disappearance of preexisting specificities, emergence of new specificities, or lack of changes. The HIV load rebounds mobilized both effector/memory HIV- and CMV-specific CD8+ lymphocytes. Therefore, frequencies of virus-specific CD8 T cells appear to be positively correlated to HIV production in most cases during highly active antiretroviral therapy, but an inverse correlation can also be observed with rapid virus changes that might involve redistribution, sequestration, or expansion of these Ag-specific CD8 T cells. Future strategies of therapeutic interruptions should take into account these various HIV-specific cell dynamics during HIV rebounds.

[Study on gene-dosage effect of high level expression of the yeast glucoamylase genes]

Diploid strains homozygous for both MAT allele and STA genes (a/a, STA1/STA1 or STA2/STA2 or STA3/STA3) and diploid strains homozygous for MAT allele but intercombinative for STA genes (a/a, STA1/STA2 or STA2/STA3 or STA1/STA3) were constructed by means of the protoplast fusion or the colchicine treatment. According to glucoamylase activity in YPS medium, we studied the gene-dosage effect and their interrelation of these three polymeric genes coding for glucoamylase. The results of the glucoamylase activity determination showed that the gene-dosage effect of glucoamylase is obvious in diploid and triploid strains homozygous for both MAT allele and STA gene, such as the glucoamylase activity of a diploid strain SFY56-6 and a triploid strain SFY56-104 homozygous for both MAT allele and STA genes were respectively 2.35 and 3.18-fold as compared with that of the their parental strain IATA-Y56 that is a haploid Saccharomyces diastaticus. Moreover, the glucoamylase activity of diploid strains homozygous for MAT allele but intercombinative for STA genes also showed the combinative gene-dosage effect to a certain extent.

[Antiretroviral therapy and immune reconstitution]

The course of the HIV infection has been dramatically modified since the introduction of highly active antiretroviral therapy (HAART) combining inhibitors of the HIV-1 reverse transcriptase and protease. Despite some controversies about the extent to which the immune system can normalize, it is generally admitted nowadays that a numerical and functional CD4 cell profile more akin to asymptomatic HIV-infected individuals can be restored in AIDS patients and can confer host protection against opportunistic events. The best hallmark of such immune restoration is the massive decline in the mortality and morbidity related to AIDS that have been registered in all industrialized countries. These changes involve a recirculation of mature peripheral T cells, a regeneration of naive T cells from thymic origin and a restoration of memory CD4 T cell réactivities. Although these recent advances warrant increased optimism, HAART by reducing the virus burden is unable to restore immunity against HIV itself, except when introduced at the very early stage after virus inoculation. The single condition required for immune reconstitution is an efficient and durable inhibition of virus replication. These positive effects can be obtained at late stages of the disease even when the patients have been heavily pre-treated. They also demonstrate that HIV does not definitively alter the lymphoid tissues nor the immune defenses, even aller years of infection and severe immune suppression, except for HIV-specific CD4 T helper cells.

Obstructive sleep apnoea syndrome: treatment update

Obstructive sleep apnoea syndrome is a common but underrecognised disorder with associated substantial morbidity and mortality. Excessive daytime sleepiness caused by the disorder leads to poor work performance and increases the risk of an individual having an automobile accident. The main objective of treatment for sleep apnoea is the relief of disabling daytime sleepiness and the improvement of quality of life. Conservative measures such as weight reduction and the avoidance of alcohol should be initiated when appropriate. Nasal continuous positive airway pressure devices have remained the standard treatment since it was first introduced in 1981. Oral appliances provide an alternative treatment choice in mild-to-moderate cases, whereas surgery is useful in selected cases.

Angiogenesis induced by the implantation of self-bone marrow cells: a new material for therapeutic angiogenesis

Bone marrow, contains various primitive cells that are thought to secrete several angiogenic growth factors and may also differentiate into endothelial cells. The present study was conducted to investigate the possibility that bone marrow cells could be a novel material to induce angiogenesis. The expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in rat bone marrow cells was examined by immunohistochemistry. The production of VEGF was compared in tissue culture supernatant under the conditions of normoxia and hypoxia. The process of angiogenesis that occurred following the implantation of bone marrow cells was determined using a rat cornea model. VEGF- and bFGF-positive cells were found in rat bone marrow. The production of VEGF from bone marrow cells was significantly more enhanced by hypoxic conditions than by normoxic conditions. The rat cornea model showed that bone marrow cell implantation created new vessels. The implantation of self-bone marrow cells is a novel and simple method of inducing angiogenesis.

Effects of augmented continuous positive airway pressure education and support on compliance and outcome in a Chinese population

OBJECTIVES

To study the effects of augmentation of continuous positive airway pressure (CPAP) education and support on compliance and outcome in patients with obstructive sleep apnea (OSA).

DESIGN

A randomized, controlled, parallel study of basic vs augmented CPAP education and support.

SETTING

A university teaching hospital.

PATIENTS

A total of 108 OSA patients randomized into basic-support (BS) and augmented-support (AS) groups.

INTERVENTIONS

Patients in the BS group (n = 54) were given educational brochures on OSA and CPAP, CPAP education by nurses, CPAP acclimatization, and were reviewed by physicians and nurses at weeks 4 and 12. Patients in the AS group (n = 54) received more education, including a videotape, telephone support by nurses, and early review at weeks 1 and 2.

MEASUREMENTS

Objective CPAP compliance, Calgary sleep apnea quality of life index (SAQLI), and cognitive function after 1 month and 3 months; and Epworth sleepiness scale (ESS) after 3 months of CPAP treatment.

RESULTS

At 4 weeks, CPAP usage was 5.3 +/- 0.2 h/night (mean +/- SEM) vs 5.5 +/- 0.2 h/night in the BS and AS groups, respectively (p = 0.4). At 12 weeks, CPAP usage was 5.3 +/- 0.3 h/night vs 5.3 +/- 0.2 h/night in the two groups, respectively (p = 0.98). There was greater improvement of SAQLI at 4 weeks (p = 0.008) and at 12 weeks (p = 0.047) in the AS group. There was no significant difference between BS and AS groups in terms of improvement of ESS and cognitive function.

CONCLUSION

Augmentation of CPAP education and support does not increase CPAP compliance, but leads to a greater improvement of quality of life during the reinforced period.

Enhancement of angiogenesis by the implantation of self bone marrow cells in a rat ischemic heart model

Background. Bone marrow contains various kinds of primitive cells which differentiate into endothelial cells and could secrete several growth factors. Therefore, we attempted to induce therapeutic angiogenesis using self bone marrow cells in a rat model. Materials and methods. Quantitative angiogenesis was examined using a sponge implantation assay that indicated whether the rat bone marrow cells had induced angiogenesis or not. Employing a rat ischemic heart model, bone marrow cells were injected directly into the ischemic area and the number of vessels was examined immunohistochemically using the anti-CD31 monoclonal antibody. The contributed growth factors revealed the levels present in the ischemic myocardium by an enzyme-linked immunosorbent assay and reverse transcription polymerase chain reaction. Results. The sponge implantation assay showed that bone marrow cells induced angiogenesis. Light microscopic analysis of the vessel count positively stained by anti-CD31 in the ischemic area showed that angiogenesis had been induced to a significantly greater degree in the group implanted with bone marrow cells (BMI group) than in the group injected with phosphate-buffered saline (PBS group) 1 week after BMI. Levels of the inflammatory cytokines interleukin-1 (IL-1beta) and cytokine-induced neutrophil chemoattractant (CINC) in the BMI group were significantly elevated compared with those in the PBS group. Conclusions. Self bone marrow cell implantation induced angiogenesis in a rat ischemic heart model as a result of elevation of the levels of IL-1beta and CINC. Thus, bone marrow implantation could be a novel and simple method to induce therapeutic angiogenesis.

Pharmacokinetic differences between rat tumour and lung tissues following isolated lung perfusion with cisplatin

Isolated lung perfusion has been performed for the treatment of unresectable lung tumours; however, the pharmacokinetics of this procedure remain unclear. This study was conducted to investigate the changes in antitumour drug concentrations in tumour and lung tissues after isolated lung perfusion, using different perfusion times and perfusate drug concentrations. Isolated left lungs were perfused for 20, 40 or 60 min with 25, 50 or 100 micrograms/ml of cisplatin after solitary lung tumour nodules were established in rats, and the total platinum concentrations in the perfused lung and tumour tissues were determined by flameless atomic absorption spectroscopy. The oedema in the perfused lung tissues was evaluated by histological examination and by the wet to dry weight ratios of the lungs. The total platinum concentration increased significantly with perfusion time and increasing perfusate cisplatin concentrations in the lung tissue, but it did not change in the tumour tissue. The wet to dry weight ratios of the lung tissues did not differ significantly among the perfusion groups. Oedema of the perfused lung tissue did not change significantly with the perfusion time or perfusate cisplatin concentration. The results of this study indicate the possibility that different pharmacokinetics exist between tumour and lung tissues following isolated lung perfusion with cisplatin, which could be used as a clinical guide for the selection of appropriate perfusion times and perfusate drug concentrations.

Sea buckthorn products: manufacture and composition

Sea buckthorn (Hippophae rhamnoides) is a unique plant currently being domesticated. The fruit is the main component of value, although the leaves are occasionally made into sea buckthorn tea. The two main sources of valuable products are derived from the berries, juice from the fleshy tissue and seed as a single seed from each berry. The juice provides a nutritious beverage, high in suspended solids and very high in vitamin C and carotenes. The juice may contain an oil phase trapped within the suspended solids, or the oil may be removed as pulp oil and provided separately. The pulp remaining after juice removal provides for extraction of "sea buckthorn yellow", a pigment that has potential use as a food coloring material. The seed is a source of seed oil, which is very unsaturated and shows promise, because of its light absorption and emollient properties, as an ingredient in cosmetics, phytopharmaceuticals, or UV skin protectant preparations. It may be prepared by conventional extraction techniques or by supercritical carbon dioxide extraction. The manufacture of the main products derived from sea buckthorn is described, including several examples from the patent literature. The available compositional data for the main products are tabulated to form a comprehensive source of information on the manufacture and composition of sea buckthorn products.

HIV-1 rebound during interruption of highly active antiretroviral therapy has no deleterious effect on reinitiated treatment. Comet Study Group

BACKGROUND

Potent antiretroviral therapy (ART) with a protease inhibitor-based regimen is commonly used to treat HIV-1-infected patients. Transient treatment interruptions because of drug intolerance or other reasons are not uncommon. HIV-1 dynamics during therapy interruption and its consequences for the subsequent reinitiation of therapy have not been properly studied.

METHODS

Ten antiretroviral-naive, HIV-1-infected subjects (mean baseline CD4 cell count of 414 cells/mm3 and plasma viral load of 4.8 log10 copies/ml) were treated with the triple drug ART regimen indinavir/zidovudine/lamivudine for 28 days. Therapy was then interrupted for 28 days, after which the same ART regimen was re-started.

RESULTS

HIV-1 in plasma declined during the first 7 days of therapy with T1/2 of 1.5 days, and during days 7-28 with T1/2 of 8.9 days. Once therapy was interrupted, a delay of 4-7 days was observed in all subjects, preceding a rapid viral rebound with a mean doubling time of 1.6 days. Mean viral load after 28 days of interruption was 96% of baseline. Upon reinitiation of the same ART regimen, viral load declined at rates similar to those observed during the initial therapy (T1/2 of 1.6 and 8.0 days, respectively). No resistance-conferring mutations were observed in the HIV-1 reverse transcriptase (RT) and protease regions after the interruption of therapy. Plasma viral loads were maintained below 200 copies/ml in subjects continuing therapy for 4 (n = 9) to 12 (n = 5) months, with a mean CD4 cell count increase of 145 cells/mm3.

CONCLUSIONS

The reintroduction of efficient ART therapy after a 1 month interruption shows viral kinetics similar to that of naive patients, and is not associated with the development of resistance. No deleterious effect on the reinitiated therapy was observed in patients who temporarily discontinued ART therapy. Nevertheless, because viral load rebounds back to baseline during treatment interruption, viral suppression is in effect put off by that period of time.

Restoration of the immune system with anti-retroviral therapy

Clinical benefits of highly active anti-retroviral treatments (HAART) are increasingly evidenced by resolving opportunistic infections and malignancies, as well as declining hospitalization and mortality rates [1]. This suggests that potent and sustained suppression of viral replication, at least to some extent, is associated with reconstitution of the immune system even in adult patients treated at advanced stages of the disease. Increased susceptibility to opportunistic infections and tumors mainly results from the loss of memory CD4+ T cell reactivity against recall antigens which is an early event in HIV disease progression. Primary responses of naive CD4+ T cells against new pathogens are suppressed even earlier in the course of HIV disease, and the progressive depletion in naive CD4+ T cells reflects profound alterations in T cell regeneration capacities. Previous studies revealed that monotherapy with ritonavir, a protease inhibitor, resulted in a slight improvement in memory CD4+ T cell responses to recall Ags only when detectable prior to onset of therapy, suggesting that the loss of CD4+ T cell reactivity might be irreversible at advanced stages of the disease [2]. In contrast our group demonstrated more recently that restoration in CD4+ T cell reactivity to specific antigens was feasible when HAART was administered in progressors [3]. Here we address some of the questions raised by immune restoration with HAART when administered at advanced stages of the disease.

[Immunologic reconstruction after antiretroviral treatment]

DATA FAVORING IMMUNE RECONSTITUTION: Multiple drug therapies for HIV infection have enabled a major reduction in the viral load, higher CD4 counts, and a lower incidence of opportunistic infections and tumor formations, and subsequently lower hospitalization rates and mortality. TWO STAGES OF CD4 RECONSTITUTION: In HIV-positive patients with advanced stage disease treated with a protease inhibitor associated with 2 nucleoside analog reverse transcriptase inhibitors and followed prospectively, it has been observed that CD4 counts rise considerably, with a rapid increase during the first 2 months followed by a slower but still positive slope over a period of 18 months. Discordant results have however also been observed suggesting an ineffective anti-viral effect or a retarded immune reconstitution. SEVERAL MECHANISMS: The lymphocyte amplification observed during the early phase corresponds to re-circulation of CD4 and CD8 lymphocytes which had been sequestered in lymphoid organs; most of these CD4 lymphocytes are memory cells. A second phase corresponds to a more moderate and progressive rise in naive CD4 cells which originate from an unknown source. This biphasic reconstitution of CD4 lymphocytes is associated with a correction of the chronic lymphocyte overactivation. PARTIAL IMMUNE RECONSTITUTION: With treatment, the capacity to respond to known antigens reappears. This restored capacity is secondary to the amplification of CD4 memory cells and appears prior to the expansion phase of naive cells. The response remains moderate and is only observed against antigens from microorganisms highly prevalent during advanced stage infection.

The long-term evaluation of pulmonary toxicity following isolated lung perfusion with melphalan in the rat

The present study was conducted to evaluate the long-term pulmonary toxicity of isolated lung perfusion (ILP) with melphalan in the rat model. F344 rats were treated by ILP with 1 mg of melphalan or buffered hespan (BHE). The rats in the melphalan group were sacrificed randomly 30, 60, 90, 120, 150, and 180 days after the perfusion. Pulmonary toxicity was evaluated by pathological analysis. In the melphalan group, light and electron microscopic findings revealed perivascular and peribronchial edema, and septal thickening with cellular infiltration of the interstitial space 30 days after the perfusion, but all of these changes had disappeared by 60 days. Azan stain showed a slight increase of the connective tissue at the alveolar wall in the melphalan group, but no progressive pulmonary interstitial fibrosis was observed after 180 days. Transmission electron microscopy showed minimal proliferation of the type II pneumocytes of normal appearance in the melphalan group. In conclusion, the long-term pulmonary toxicity of ILP with melphalan is acceptable; however clinical trials of this therapy need to be conducted.

Isolated lung perfusion with cisplatin in a rat lung solitary tumor nodule model

BACKGROUND

The present study was conducted to evaluate the toxicity, pharmacokinetics and anti-tumor potency of isolated lung perfusion (ILP) with cisplatin in a visible lung tumor nodule model in rats.

MATERIALS AND METHODS

A solitary tumor nodule was established by the injection of Methylcholanthrene-induced sarcoma cells into the left lung. Thirty rats were randomized to undergo ILP with either 0.1, 0.25, or 0.5 mg/mL cisplatin and buffered hespan (BHE), or with an intravenous injection of 1.0 or 2.5 mg cisplatin.

RESULTS

The highest dose of cisplatin tolerated by the rats was 0.1 mg/mL for perfusion. A much higher platinum concentration in the tumor, of 6.67 +/- 1.64 vs. 2.51 +/- 0.60 micrograms/g tissue, but a significantly lower concentration in the serum and kidneys, was achieved by perfusion compared to that achieved by intravenous injection. A significantly lower tumor weight and 20% complete treatment response was achieved in rats given cisplatin than in those given BHE perfusion at 43.9 +/- 11.6 vs. 226.3 +/- 44.6 mg.

CONCLUSION

ILP with cisplatin achieved superior results to intravenous injection according to the levels of toxicity and pharmacokinetic analysis, and it was effective against a visible tumor nodule model in rats.