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Pulmonary vascular disease is not a single condition; rather it can accompany a variety of pathologies that impact the pulmonary vasculature. Applying precision medicine strategies to better phenotype, diagnose, monitor, and treat pulmonary vascular disease is increasingly possible with the growing accessibility of powerful clinical and research tools. Nevertheless, challenges exist in implementing these tools to optimal effect. The 2023 Grover Conference Series reviewed the research landscape to summarize the current state of the art and provide a better understanding of the application of precision medicine to managing pulmonary vascular disease. In particular, the following aspects were discussed: (1) Clinical phenotypes, (2) genetics, (3) epigenetics, (4) biomarker discovery, (5) application of precision biology to clinical trials, (6) the right ventricle (RV), and (7) integrating precision medicine to clinical care. The present review summarizes the content of these discussions and the prospects for the future., Competing Interests: ARH has served as a consultant for United Therapeutics, Bayer, GossamerBio, Merck, Janssen and Tenax Therapeutics and has stock in Tenax Therapeutics. AJ has previously served on an advisory board for Janssen (12/2023. GAH receives funding from Bayer Healthcare: non‐branded Speakers Bureau, Advisory Boards, and Research Funding; and Janssen Pharmaceuticals: Clinical Trial Steering Committee and Advisory Boards., (© 2025 The Author(s). Pulmonary Circulation published by John Wiley & Sons Ltd on behalf of Pulmonary Vascular Research Institute.)

Preclinical studies suggest mesenchymal stromal cell extracellular vesicles (MSC-EVs) reduce inflammation and improve organ function in lung diseases; however, an objective analysis of all available data is needed prior to translation. Using rigorous meta-research methods, we determined the effectiveness of MSC-EVs for preclinical respiratory diseases and identified experimental conditions that may further refine this therapy. A systematic search of MEDLINE/Embase identified 1167 records. After screening, 52 articles were included for data extraction and evaluated for risk of bias and quality of reporting in study design. A random effects meta-analysis was conducted for acute lung injury (ALI; N = 23), bronchopulmonary dysplasia (BPD; N = 8) and pulmonary arterial hypertension (PAH; N = 7). Subgroup analyses identified EV methods/characteristics that may be associated with improved efficacy. Data is presented as standardized mean differences (SMD) or risk ratios (RR) with 95% confidence intervals (CI). For ALI, MSC-EVs markedly reduced lung injury (SMD -4.33, CI -5.73 to -2.92), vascular permeability (SMD -2.43, CI -3.05 to -1.82), and mortality (RR 0.39, CI 0.22 to 0.68). Small EVs were more consistently effective than large EVs whereas no differences were observed between tissue sources, immunocompatibility or isolation techniques. For BPD, alveolarization was improved by MSC-EVs (SMD -1.45, CI -2.08 to -0.82) with small EVs more consistently beneficial then small/large EVs. In PAH, right ventricular systolic pressure (SMD -4.16, CI -5.68 to -2.64) and hypertrophy (SMD -2.80, CI -3.68 to -1.91) were significantly attenuated by EVs. In BPD and PAH, EVs isolated by ultracentrifugation demonstrated therapeutic benefit whereas tangential flow filtration (N = 2) displayed minimal efficacy. Lastly, risk of bias and quality of reporting for experimental design were consistently unclear across all studies. Our findings demonstrate clear potential of MSC-EVs to be developed as therapy for acute and chronic lung diseases. However, greater transparency in research design and direct comparisons of isolation technique and EV subtypes are needed to generate robust evidence to guide clinical translation. Protocol Registration: PROSPERO CRD42020145334., (© 2021 The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals, LLC on behalf of the International Society for Extracellular Vesicles.)

Micro-computed tomography (micro-CT) is used in pre-clinical research to generate high-resolution three-dimensional (3D) images of organs and tissues. When combined with intravascular contrast agents, micro-CT can provide 3D visualization and quantification of vascular networks in many different organs. However, the lungs present a particular challenge for contrast perfusion due to the complexity and fragile nature of the lung microcirculation. The protocol described here has been optimized to achieve consistent lung perfusion of the microvasculature to vessels < 20 microns in both normal and pulmonary arterial hypertension rats. High-resolution 3D micro-CT imaging can be used to better visualize changes in 3D architecture of the lung microcirculation in pulmonary vascular disease and to assess the impact of therapeutic strategies on microvascular structure in animal models of pulmonary arterial hypertension., (© The Author(s) 2019.)

Background: This randomized phase 2 trial compared the efficacy and safety of second-line nanoparticle albumin-bound paclitaxel (nab-paclitaxel) with or without the addition of CC-486 (an oral formulation of 5-azacytidine) in patients with advanced-stage, nonsquamous non-small cell lung cancer., Methods: Patients were randomized to receive either nab-paclitaxel 100 mg/m 2 on days 8 and 15 plus CC-486 200 mg daily on days 1 to 14 or single-agent nab-paclitaxel 100 mg/m 2 on days 1 and 8, with both regimens administered every 21 days until tumor progression or unacceptable toxicity. The primary endpoint was progression-free survival. Secondary endpoints included the overall response rate, the disease control rate, and overall survival., Results: Between January 2015 and August 2016, 161 patients were randomized (81 to the combination arm and 80 to the single-agent nab-paclitaxel arm). There was no benefit from the addition of CC-486 to nab-paclitaxel. The median progression-free survival was 3.2 months for the combination and 4.2 months for single-agent nab-paclitaxel (hazard ratio, 1.3; 95% confidence interval, 0.9-1.9). The median overall survival was 8.1 months in the combination arm and 17 months in the single-agent nab-paclitaxel arms (hazard ratio, 1.7; 95% confidence interval, 1.08-2.57). Grade 3 or greater treatment-related, emergent adverse events were reported by 40.5% of patients in the combination arm and by 31.6% of those in the single-agent nab-paclitaxel arm., Conclusions: Single-agent nab-paclitaxel was associated with promising outcomes and a tolerable safety profile as second-line treatment for patients with advanced-stage, nonsquamous non-small cell lung cancer. There was no benefit from the addition of CC-486 to nab-paclitaxel., (© 2018 American Cancer Society.)

Background and Purpose: Pulmonary arterial hypertension (PAH) is a life-threatening disease that leads to progressive pulmonary hypertension, right heart failure and death. Parenteral prostaglandins (PGs), including treprostinil, a prostacyclin analogue, represent the most effective medical treatment for severe PAH. We investigated the effect of treprostinil on established severe PAH and underlying mechanisms using the rat SU5416 (SU, a VEGF receptor-2 inhibitor)-chronic hypoxia (Hx) model of PAH., Experimental Approach: Male Sprague Dawley rats were injected with SU (20 mg·kg -1 , s.c.) followed by 3 weeks of Hx (10% O 2 ) to induce severe PAH. Four weeks post-SU injection, baseline right ventricular (RV) systolic pressure (RVSP) was measured, and the rats were randomized to receive vehicle or treprostinil treatment (Trep-100: 100 ng·kg -1 ·min -1 or Trep-810: 810 ng·kg -1 ·min -1 ). Following 3 weeks of treatment, haemodynamic and echocardiographic assessments were performed, and tissue samples were collected for protein expression and histological analysis., Key Results: At week 7, no difference in RVSP or RV hypertrophy was observed between vehicle and Trep-100; however, Trep-810 significantly reduced RVSP and RV hypertrophy. Trep-810 treatment significantly improved cardiac structure and function. Further, a short-term infusion of treprostinil in rats with established PAH at 4 weeks post-SU produced an acute, dose-dependent reduction in RVSP consistent with a vasodilator effect. However, chronic Trep-810 treatment did not alter media wall thickness, degree of vascular occlusion or total vessel count in the lungs., Conclusions and Implications: Treprostinil exerts therapeutic benefits in PAH through decreased vascular resistance and improved cardiac structure and function; however, treprostinil treatment does not have direct impact vascular remodelling., (© 2018 The British Pharmacological Society.)

Reversing pathologic alterations in vascular microRNA (miRNA) expression represents a potential therapeutic strategy for pulmonary hypertension. While polyethylenimine (PEI) has previously been shown to be an effective vehicle for vascular lung-directed delivery of plasmid DNA, it remains unclear whether this utility is generalizable to miRNAs. Here we show that despite elevated lung levels, the intravenous infusion of PEI-miRNA mimic complexes fails to provide lung-selective delivery in rats.

Translational research depends on the relevance of animal models and how well they replicate human disease. Here, we investigated plasma levels of three important pro-inflammatory cytokines (TNFα, IL-6, and MCP-1), known to be elevated in human pulmonary arterial hypertension (PAH), and systematically assessed their levels in PAH patients compared to five different rodent models of pulmonary hypertension (PH). A consistent immunoassay platform (Luminex xMAP) and source (Millipore) was used to measure all specimens. PAH patients (n = 29) exhibited significant elevations in all three cytokines (median [IQR] pg/mL; TNFα, 7.0 [4.8-11.7]; IL-6, 9.2 [3.8-17.2]; MCP-1, 109 [65-142]) versus healthy participants (n = 20) (median [IQR] pg/mL; TNFα, 3.0 [2.0-3.6]; IL-6, 1.7 [0.5-7.2]; MCP-1, 79 [49-93]. In contrast, mice with PH established after three weeks of hypoxia (n = 18) or SU5416 plus hypoxia (n = 20) showed no significant change in their plasma cytokine levels versus controls (n = 16), based on three to four independent experiments per group. Similarly, plasma cytokine levels were not elevated in rats with PH established three weeks after monocrotaline (n = 23), eight weeks after SU5416 alone (n = 10) or six to eight weeks after SU5416 plus hypoxia (n = 21) versus controls (n = 36 rats), based on three to eight independent experiments per group. Positive biologic control specimens from sepsis patients (n = 9), cecal-ligation and puncture (CLP)-induced septic mice (n = 6), and lipopolysaccharide-induced septic rats (n = 4) showed robust elevations in all three cytokines. This study suggests that animal models commonly used for the development of novel diagnostic and therapeutic approaches for PAH may have limited construct validity with respect to markers of systemic immune activation seen in human patients.

Interferon (IFN) therapy has an important role in the treatment of multiple sclerosis and chronic hepatitis C infection. A few case reports have described an association between IFN therapy and the development of irreversible pulmonary arterial hypertension (PAH), and it is currently listed as a possible drug-induced cause of PAH in the most recent classification of pulmonary hypertension. A causal link between IFN use and PAH remains to be elucidated; many reports of PAH resulting from IFN occur in individuals with some other risk factor for PAH. The authors present a case involving a patient with multiple sclerosis with no known risk factors for PAH, who developed severe PAH after exposure to IFN therapy. The patient experienced significant clinical and hemodynamic improvement, with normalization of her pulmonary pressures after the initiation of combination therapy for PAH. At 28 months after diagnosis, she remains asymptomatic with no hemodynamic evidence of PAH and has been off all PAH therapy for 10 months.

Accurate prognostic prediction is challenging for patients with advanced-stage non-small cell lung cancer (NSCLC). We systematically investigated genetic variants within inflammation pathways as potential prognostic markers for advanced-stage NSCLC patients treated with first-line chemotherapy. A discovery phase in 502 patients and an internal validation phase in 335 patients were completed at the MD Anderson Cancer Center. External validation was performed in 371 patients at Harvard University. A missense single-nucleotide polymorphism (SNP) in the gene encoding the major histocompatibility complex class II, DO-β chain (HLA-DOB:rs2071554), predicted to influence protein function, was significantly associated with poor survival in the discovery (hazard ratio (HR): 1.46; 95% confidence interval (CI): 1.02-2.09), internal validation (HR: 1.51; 95% CI: 1.02-2.25), and external validation (HR: 1.52; 95% CI: 1.01-2.29) populations. KLRK1:rs2900420 was associated with reduced risk in the discovery (HR: 0.76; 95% CI: 0.60-0.96), internal validation (HR: 0.77; 95% CI: 0.61-0.99), and external validation (HR: 0.80; 95% CI: 0.63-1.02) populations. A strong cumulative effect on overall survival was observed for these SNPs. Genetic variations in inflammation-related genes could have potential to complement prediction of prognosis.

The objective of this study was to evaluate the effects of local endothelial progenitor cell (EPC) therapy on bone regeneration in a rat model. A segmental bone defect (5 mm) was created in the femur and fixed with a mini-plate. There were two groups: EPC-treated (N = 28) and control (N = 28). Seven animals were sacrificed from each group at 1, 2, 3, and 10 weeks postoperatively. Healing of the defect was evaluated with radiographic, histological, and quantitative micro-computed tomography (micro-CT) scans. Radiographically, mean scores of the EPC and control groups were, respectively, 1.16-0.61 (p < 0.05) at 1 week, 2.53-1.54 (p < 0.05) at 2 weeks, and 4.58-2.35 at 3 weeks (p < 0.05). At 10 weeks, all the animals in the EPC-treated group had complete union (7/7), but in the control group none achieved union (0/7). Histological evaluation revealed that specimens from EPC-treated animals had abundant new bone and vessel formation compared to that in controls. Micro-CT assessment of the samples from the animals sacrificed at 10 weeks (N = 14) showed significantly improved parameters of bone volume (36.58-10.57, p = 0.000), bone volume density (0.26-0.17, p = 0.000), model index -2.22-2.79, p = 0.000), trabecular number (1.28-0.91, p = 0.063), trabecular thickness (0.21-0.15, p = 0.001), trabecular spacing (0.63-1.07, p = 0.022), bone surface (353.75-152.08, p = 0.000), and bone surface to bone volume ratio (9.54-14.24, p = 0.004) for the EPC group compared to control, respectively. In conclusion, local EPC therapy significantly enhanced bone regeneration in a segmental defect model in rat femur diaphysis., (Copyright 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Background: Irinotecan has significant activity in small-cell lung cancer (SCLC). The authors' previous phase 1 study of alternating weekly therapy with irinotecan/cisplatin (IP), etoposide/cisplatin (EP), and granulocyte-colony-stimulating factor (G-CSF) support was well tolerated and active in patients with SCLC. A phase 2 trial was conducted to estimate the efficacy of this regimen in previously untreated patients with extensive SCLC., Methods: A total of 33 patients were treated between June 2002 and July 2007. Patients received 12 weeks of therapy with cisplatin (20 mg/m(2)) on Day 1 and irinotecan (100 mg/m(2)) on Day 1 and G-CSF on Days 2 to 5 (Weeks 1, 3, 5, 7, 9, and 11) followed by cisplatin (20 mg/m(2)) on Day 1 and etoposide (60 mg/m(2)) on Days 1 to 3 with G-CSF on Days 4 to 7 (Weeks 2, 4, 6, 8, 10, and 12). The primary endpoint was 1-year survival rate., Results: Grade 4 neutropenia (toxicities were determined using the National Cancer Institute Common Toxicity Criteria [version 2.0]) was noted in 5 (1.5%) of 343 courses with neutropenic fever in only 5 (1%) of 343 courses. One patient died of neutropenic sepsis. Nonhematologic toxicities grade >or=2 were observed in 15 (4%) of 343 courses and were limited to fatigue, hyponatremia, and diarrhea. The overall objective response rate was 89% in 28 assessable patients (no complete responses and 25 partial responses). The median progression-free and overall survivals were 6.0 months and 10.9 months, respectively. The 1-year survival rate was 33%., Conclusions: Weekly therapy with IP alternating with EP and G-CSF support was well tolerated in patients with extensive SCLC, but did not demonstrate improved progression-free or overall survival when compared with historical controls at the study institution., ((c) 2010 American Cancer Society.)

Background: The staging system for non-small cell lung cancer (NSCLC) does not consider tumor burden or number of metastatic sites, although oligometastases are more favorable., Methods: Using log-rank testing, the authors analyzed overall survival (OS) in 1284 patients newly presenting with metastatic NSCLC by number of metastatic organ sites and the presence of brain metastases., Results: OS for patients without brain metastases was found to be correlated with the number of metastatic sites (P = .0009). Brain metastases conferred an inferior OS (median of 7 months vs 9 months; 95% confidence interval, 7-8 months vs 8-10 months [P = .00,002]). To evaluate the influence of tumor burden on OS, the authors considered subsets of patients in whom the brain (n = 135) or lung (n = 137) was the solitary metastatic organ site. In patients with brain metastases, OS was found to be correlated inversely with the volume of all metastases or the largest lesion (hazards ratio, 1.04 or 1.03, respectively; P = .01). For patients with lung metastases, OS was better for those with a maximum tumor size below the median of 40 mm (P = .0004)., Conclusions: Staging of NSCLC and clinical trial patient stratification should include quantitation of tumor burden. The prognostic impact of brain metastases is small and partly dependent on tumor volume, which indicates the need for aggressive therapy for patients with NSCLC brain metastasis and their inclusion in clinical trials.

Fracture healing requires coordinated coupling between osteogenesis and angiogenesis in which vascular endothelial growth factor (VEGF) plays a key role. We hypothesized that targeted over-expression of angiogenic and osteogenic factors within the fracture would promote bone healing by inducing development of new blood vessels and stimulating/affecting proliferation, survival, and activity of skeletal cells. Using a cell-based method of gene transfer, without viral vector, 5.0 x 10(6) fibroblasts transfected with VEGF were delivered to a 10-mm bone defect in rabbit tibiae (Group 1) (n = 9); control groups were treated with fibroblasts (Group 2) (n = 7), or saline (Group 3) (n = 7) only. After 12 weeks, eight tibial fractures healed in Group 1, compared to four each in Groups 2 and 3. In Group 1, ossification was seen across the entire defect; in Groups 2 and 3, the defects were fibrous and sparsely ossified. Group 1 had more positively stained (CD31) vessels than Groups 2 and 3. MicroCT 3-D showed complete bridging of the new bone for Group 1, but incomplete healing for Groups 2 and 3. MicroCT bone structural parameters showed significant differences between VEGF treatment and control groups (p < 0.05). These results indicate that the cell-based VEGF gene therapy has significant angiogenic and osteogenic effects to enhance healing of a segmental defect in the long bone of rabbits.

The induction of therapeutic angiogenesis with gene therapy approaches has received considerable interest and some limited clinical success. A major drawback to this approach is a lack of understanding of the pharmacokinetics of therapeutic protein delivery. This has become increasingly more relevant as recent studies have illustrated a defined therapeutic window for angiogenic protein secretion into the local microenvironment. For cell based gene therapies, with cells widely distributed throughout the tissue, this implies that any individual cell must attain a specific secretion rate to produce a local angiogenic response. Here we report a reproducible technique enabling the study of growth factor secretion from individual cells following transient plasmid transfection. We demonstrate significant variability in single cell vascular endothelial growth factor (VEGF) secretion with the majority of total protein secretion arising from a small subpopulation of transfected cells. We demonstrate that VEGF secretion is linearly correlated to intracellular plasmid copy number and protein secretion does not appear to reach saturation within the cell population. The selection of gene therapy approaches that optimize individual cell secretion profiles may be essential for the development of effective gene therapies.

The Canadian Cardiovascular Society and the Canadian Thoracic Society requested a position statement on pulmonary arterial hypertension from leading Canadian experts. The present document is intended to act as an update for the clinician, to provide a template for the initial evaluation of patients, to enable the understanding of current therapeutic paradigms based on approved indications for Canada, to highlight new therapies on the horizon, and to state the positions of the Canadian Cardiovascular Society and the Canadian Thoracic Society on resource management for pulmonary arterial hypertension in Canada.

The reduction in antibody observed following inoculation with multiple heterologous Dichelobacter nodosus pili antigens is thought to be due to competition between antigen-specific B cells for a limited amount of T cell help. We demonstrate here that this competition is not further influenced by the expansion of cross-reactive antibody secreting cells at the expense of serogroup specific antibody secreting cells. The T cell determinants of pili recognized by sheep and BALB/c mice have been defined using 15 residue peptides. These T cell determinants include cross-reactive determinants in the conserved amino terminal region of the antigen. Here we investigate the effect of expanding the pili-specific T cell population by priming with pili derived T cell determinants. It was not possible to increase the antibody elicited in response to the multivalent vaccine by priming mice with either a synthetic peptide spanning a T cell determinant or with reduced and alkylated or heterologous serogroups of pili 4 weeks before inoculation with the multivalent vaccine. A strategy designed to increase the T cell population by inoculating animals with pili covalently coupled to an extrinsic T cell determinant was pursued.

The effects of ibotenic acid lesion of the septum were studied in rats implanted with chronically indwelling electrodes and septal cannula. Each rat served as its own control and the properties of the hippocampal theta rhythm were studied before and after ibotenic acid and control saline infusion into the medial septal area. Ibotenic acid preferentially killed neurons in the lateral septum, and significantly attenuated the hippocampal theta rhythm about 50% bilaterally, at both surface and deep electrodes. The coherence and the phase of the theta rhythm at the CA1 apical dendrites, with respect to a superficial electrode, also declined significantly after ibotenic acid lesion. Pilocarpine (25 mg/kg i.p.) induced a theta rhythm of 7-9 Hz during immobility in the lesioned rats that was significantly higher in frequency than that induced in intact rats (4-6 Hz). In lesioned rats, the theta rhythm during tail pinch under urethane anesthesia was largely abolished, and the theta during walking was attenuated by atropine sulfate (50 mg/kg i.p.). Phencyclidine (10 mg/kg i.p.) or parachlorophenylalanine (PCPA) alone, which was inferred to abolish an atropine-resistant theta input, did not affect the power of the walking theta rhythm in either the lesioned or the normal rat. It was concluded that the theta in the behaving rats after ibotenic acid lesion in the septum has a strong atropine-sensitive component, and that it is not predominantly atropine-resistant, as suggested previously. The lack of PCPA effect on the theta phase in intact and lesioned rats also suggested a different view of the atropine-resistant theta in hippocampal region CA1. One possible mechanism of the atropine-resistant theta at the distal dendrites of pyramidal cells may result from rhythmic inhibition by stratum lacunosum-moleculare interneurons which may be activated by either serotonergic or cholinergic inputs.

Of 22 patients with hairy cell leukemia, 18 developed life-threatening infections. Susceptibility to infection appeared to be increased nonspecifically, in that a wide range of infecting organisms were noted. Pseudomonas aeruginosa was the organism isolated most frequently. Four patients had disseminated Mycobacterium kansasii, and one had bacillus Calmette-Guerin lymphadenitis. Two patients developed serious fungal infections (Candida albicans in one and Allescheria boydii in the other). One patient had disseminated cytomegalovirus infection and two had toxoplasmosis. Splenectomy did not appear to decrease the infection rate. The infection rate initially increased following chemotherapy (P less than 0.001), then returned to pretreatment levels by two months following treatment. Infections were most frequent during granulocytopenia (P less than 0.01), but granulocytopenia was not a prerequisite for either life-threatening or fatal infections. Monocytopenia may be a more important factor than granulocytopenia in risk of infection in hairy cell leukemia patients.

The hydrolysis of cocaine and its N-demethylated product, norcocaine, by esterases was examined in liver and serum. Both liver and serum enzymatically formed ecgonine methyl ester from cocaine. The liver enzyme had a much lower affinity for cocaine than that of serum, indicating that a different form of esterase was present in liver. The liver enzyme had a similar affinity for both norcocaine and cocaine. Likewise, the serum enzyme showed similar affinities for both substrates. The Vmax estimates, however, were consistently higher for norcocaine than cocaine in both liver and serum. Benzoyl ecgonine, a major metabolite of cocaine formed by hydrolysis, was not produced enzymatically in either serum or liver; the rate of spontaneous formation at physiological pH suggests that this metabolite may arise nonenzymatically in the body.

Prognostic factors were examined in 31 patients with hairy cell leukemia seen at M. D. Anderson Hospital. Long survival from presentation was significantly associated with ease of aspiration of iliac crest bone marrow, absence of major infection, hemoglobin greater than 10 g/dl, and absence of a prior history of pneumonia. Long survival from splenectomy was associated most closely with absence of a prediagnosis history of pneumonia, suggesting that a long-standing host defense abnormality may exist that is not corrected by splenectomy. Generally, patients with sustained improvement in hematologic parameters postsplenectomy lived longest from splenectomy, although the results were not statistically significant.

The frequency of prior occupational, accidental, or therapeutic radiation exposure was significantly higher for hairy cell leukemia patients than for a control group of solid tumor patients (8/23 vs. 4/56, P < 0.01). Hairy cell leukemia patients were also more frequently involved in occupations at high risk of radiation exposure such as chemist, engineer, physicist, and health care facility worker (7/23 vs. 4/56, P < 0.01). The observation that the incidence of thyroid disorders among hairy cell leukemia patients was also unusually high (5/23 vs. 2/56, P < 0.05) was interpreted as further indirect evidence of excessive radiation exposure. It appears that radiation exposure may be an important contribution factor in the development of some case of hairy cell leukemia.

Eighty-seven adult patients who had achieved bone marrow remission of leukemia developed one or more episodes of meningeal leukemia. Multiple patient characteristics were examined for their effect on probability of achieving complete remission from meningeal disease and for their effect on duration of meningeal remission. Presence of obtundation (P less than 0.01) or other symptoms of meningeal disease (P = 0.02) were associated with a low remission induction rate. Other factors which tended (P = 0.06-0.20) to be associated with low remission induction rates included high cerebrospinal fluid (CSF) opening pressure, absence of splenomegaly at initial diagnosis, high peripheral blood leukocyte count (WBC) at the episode of marrow disease most recently preceding the meningeal disease, and use of only one as opposed to two or more intrathecal drugs as treatment. Factors associated with long duration of meningeal remissions included diagnosis (AML greater than acute undifferentiated leukemia greater than ALL, P = 0.05), absence of symptoms (P = 0.04), low CSF WBC (P = 0.01), rapid attainment of meningeal remission (P = 0.01), rapid attainment of initial bone marrow remission (P = 0.02), and long duration of initial bone marrow remission (P less than 0.01). Absence of cranial or peripheral neuropathies, low CSF protein and opening pressure, and short time interval between diagnosis of marrow and meningeal disease also tended (P = 0.06-0.20) to be associated with long meningeal remissions. Patients treated according to an intensive protocol utilizing cranial irradiation and triple drug treatment via an Ommaya reservoir had substantially longer meningeal remissions than did patients treated with less intensive therapy (P = 0.01). Relapse-free survival curves suggest that some patients are cured of their meningeal disease.

Thirty-five patients with malignant brain tumors (23 with primary brain tumors and 12 with brain metastases) progressing after cranial irradiation +/- chemotherapy received cisplatin, 60 to 120 mg/m2, into the internal carotid artery by a transfemoral approach. Courses of therapy were repeated every 4 weeks. Therapeutic evaluation was performed monthly using the CT scan of the brain and clinical neurologic examination. Thirty patients were evaluable for response. Of 20 evaluable patients with primary malignant brain tumors, 6 responded to therapy and 5 had stable disease. The median time to tumor progression for responding patients was 33 weeks, for stable patients 16 weeks, and 13 weeks for all patients. Five of 10 evaluable patients with brain metastases responded to intracarotid cisplatin, and 2 patients had stable disease. The estimated median time to progression for responding patients was 30+ weeks and 12+ weeks for patients with stable disease. Side effects included seizures in 5 courses, mental agitation and motor restlessness in 1, and transient hemiparesis in 7. One patient may have had a drug-related death, and one patient appeared to develop encephalopathy after treatment. Five patients had clinical deterioration in vision; in two patients it was bilateral. Intracarotid cisplatin has definite activity in patients with malignant primary brain tumors and in patients with brain metastases. The recommended starting dose for intracarotid cisplatin is 60 to 75 mg/m2. At this dose level side effects are uncommon, but includes the risk of neurologic and retinal toxicity.

Central nervous system (CNS) involvement occurred in 45 of 222 (20.3%) leukemic adults achieving bone marrow (BM) complete remission (CR), including 12 of 23 (52%) acute undifferentiated leukemia (AUL), 12 of 32 (39%) lymphoma leukemia, 5 of 26 (19%) acute lymphoblastic leukemia, and 16 of 142 (11%) acute myelogenous leukemia. Risk factors for CNS disease were lactic dehydrogenase (LDH) greater than or equal to 25,000/mm3. AUL morphology, age less than 20 years, and extramedullary involvement were most significant. Pattern of CNS involvement varied with morphology. Survival after CNS relapse depended most on BM status and symptoms. Duration of CNS CR was longest for asymptomatic patients with low CSF cell counts. Also important were duration of first BM CR, ease of achievement of initial BM CR, and leukocyte count (original and at most closely antecedent BM involvement), reflecting the common origin of BM and CNS leukemic cells. Central nervous system relapse generally did not shorten BM CR or survival, although early primary CNS relapse was associated with early BM relapse.

A total of 17 monoclonal antibodies (MoAb) were used to analyse the antigenic structure of pilus protein from three serogroups of Bacteroides nodosus. The four MoAb which agglutinated pili were serogroup (and subgroup) specific, and the agglutinating epitope was present on the pili monomer and dependent on the intra-chain disulfide bond. Non-agglutinating MoAb identified two further non-linear and serogroup-restricted epitopes on strain 198 (A1) pili and two linear epitopes on 336 (F1) and 265 (H1) pili. Three MoAb cross-reacted with pili from six of the eight major serogroups and recognized an epitope in the N-terminal region of the molecule. This panel of MoAb has therefore identified at least four epitopes on pilus protein and will facilitate serotopic analyses of the immunogenicity of each epitope in sheep during vaccination against footrot.

Following ingestion of [N-14CH3]cocaine (10 mg, 2.3 muCi) by 2 healthy subjects, breath, saliva, serum, and urine samples were collected serially. Labeled CO2 production was monitored as a measure of N-demethylation of cocaine. The cumulative excretion of 14CO2 in 5 hr was 2.4% and 6.2% of the administered dose with half-lives of 2.3 and 1.4 hr, respectively. The greater N-demethylation was found in a subject with lower plasma cholinesterase activity. Radioactivity excreted in 0 to 28 hr urine reached 65% to 75% of the dose. Ecgonine methyl ester, a product of cocaine hydrolysis by plasma cholinesterase, was identified as a major metabolite in the urine of both subjects and accounted for 32% to 49% of the urinary metabolites.