Distinct tumor-infiltrating lymphocyte landscapes are associated with clinical outcomes in localized non-small-cell lung cancer.

BACKGROUND: Despite the importance of tumor-infiltrating T lymphocytes (TILs) in cancer biology, the relationship between TIL phenotypes and their prognostic relevance for localized non-small-cell lung cancer (NSCLC) has not been well established. PATIENTS AND METHODS: Fresh tumor and normal adjacent tissue was prospectively collected from 150 patients with localized NSCLC. Tissue was comprehensively characterized by high-dimensional flow cytometry of TILs integrated with immunogenomic data from multiplex immunofluorescence, T-cell receptor sequencing, exome sequencing, RNA sequencing, targeted proteomics, and clinicopathologic features. RESULTS: While neither the magnitude of TIL infiltration nor specific TIL subsets were significantly prognostic alone, the integration of high-dimensional flow cytometry data identified two major immunotypes (IM1 and IM2) that were predictive of recurrence-free survival independent of clinical characteristics. IM2 was associated with poor prognosis and characterized by the presence of proliferating TILs expressing cluster of differentiation 103, programmed cell death protein 1, T-cell immunoglobulin and mucin-domain containing protein 3, and inducible T-cell costimulator. Conversely, IM1 was associated with good prognosis and differentiated by an abundance of CD8+ T cells expressing cytolytic enzymes, CD4+ T cells lacking the expression of inhibitory receptors, and increased levels of B-cell infiltrates and tertiary lymphoid structures. While increased B-cell infiltration was associated with good prognosis, the best prognosis was observed in patients with tumors exhibiting high levels of both B cells and T cells. These findings were validated in patient tumors from The Cancer Genome Atlas. CONCLUSIONS: Our study suggests that although the number of infiltrating T cells is not associated with patient survival, the nature of the infiltrating T cells, resolved in distinct TIL immunotypes, is prognostically relevant in NSCLC and may inform therapeutic approaches to clinical care.

A global inventory of photovoltaic solar energy generating units.

Photovoltaic (PV) solar energy generating capacity has grown by 41 per cent per year since 20091. Energy system projections that mitigate climate change and aid universal energy access show a nearly ten-fold increase in PV solar energy generating capacity by 20402,3. Geospatial data describing the energy system are required to manage generation intermittency, mitigate climate change risks, and identify trade-offs with biodiversity, conservation and land protection priorities caused by the land-use and land-cover change necessary for PV deployment. Currently available inventories of solar generating capacity cannot fully address these needs1-9. Here we provide a global inventory of commercial-, industrial- and utility-scale PV installations (that is, PV generating stations in excess of 10 kilowatts nameplate capacity) by using a longitudinal corpus of remote sensing imagery, machine learning and a large cloud computation infrastructure. We locate and verify 68,661 facilities, an increase of 432 per cent (in number of facilities) on previously available asset-level data. With the help of a hand-labelled test set, we estimate global installed generating capacity to be 423 gigawatts (-75/+77 gigawatts) at the end of 2018. Enrichment of our dataset with estimates of facility installation date, historic land-cover classification and proximity to vulnerable areas allows us to show that most of the PV solar energy facilities are sited on cropland, followed by aridlands and grassland. Our inventory could aid PV delivery aligned with the Sustainable Development Goals.

Combination therapy with topotecan, paclitaxel, and bevacizumab improves progression-free survival in recurrent small cell neuroendocrine carcinoma of the cervix.

OBJECTIVES: To assess if the combination of topotecan, paclitaxel, and bevacizumab (TPB) was active in recurrent SCCC and to compare the survival of patients with SCCC who received TPB to a group of women with SCCC who did not receive this regimen. METHODS: We retrospectively analyzed women with recurrent SCCC who received chemotherapy as primary therapy. Women treated with TPB for first recurrence were compared to women treated with non-TPB chemotherapy. RESULTS: Thirteen patients received TPB, and 21 received non-TPB chemotherapy, most commonly platinum with or without a taxane. Median progression-free survival (PFS) was 7.8months for TPB and 4.0months for non-TPB regimens (hazard ratio [HR] 0.21, 95% CI 0.09-0.54, P=0.001). Median overall survival (OS) was 9.7months for TPB and 9.4months for non-TPB regimens (HR 0.53, 95% CI 0.23-1.22, P=0.13). Eight women (62%) who received TPB versus four (19%) who received non-TPB regimens were on treatment for >6months (P=0.02), and four patients (31%) in the TPB group versus two (10%) in the non-TPB group were on treatment for >12months (P=0.17). In the TPB group, three patients (23%) had complete response, two (15%) had complete response outside the brain with progression in the brain, 3 (23%) had a partial response, 2 (15%) had stable disease, and 3 (23%) had progressive disease. CONCLUSIONS: These findings indicate that TPB for recurrent SCCC significantly improved PFS over non-TPB regimens, and trends towards improved OS. Furthermore, a significant number of patients had a durable clinical benefit.

ZEB1 induces LOXL2-mediated collagen stabilization and deposition in the extracellular matrix to drive lung cancer invasion and metastasis.

Lung cancer is the leading cause of cancer-related deaths, primarily due to distant metastatic disease. Metastatic lung cancer cells can undergo an epithelial-to-mesenchymal transition (EMT) regulated by various transcription factors, including a double-negative feedback loop between the microRNA-200 (miR-200) family and ZEB1, but the precise mechanisms by which ZEB1-dependent EMT promotes malignancy remain largely undefined. Although the cell-intrinsic effects of EMT are important for tumor progression, the reciprocal dynamic crosstalk between mesenchymal cancer cells and the extracellular matrix (ECM) is equally critical in regulating invasion and metastasis. Investigating the collaborative effect of EMT and ECM in the metastatic process reveals increased collagen deposition in metastatic tumor tissues as a direct consequence of amplified collagen gene expression in ZEB1-activated mesenchymal lung cancer cells. In addition, collagen fibers in metastatic lung tumors exhibit greater linearity and organization as a result of collagen crosslinking by the lysyl oxidase (LOX) family of enzymes. Expression of the LOX and LOXL2 isoforms is directly regulated by miR-200 and ZEB1, respectively, and their upregulation in metastatic tumors and mesenchymal cell lines is coordinated to that of collagen. Functionally, LOXL2, as opposed to LOX, is the principal isoform that crosslinks and stabilizes insoluble collagen deposition in tumor tissues. In turn, focal adhesion formation and FAK/SRC signaling is activated in mesenchymal tumor cells by crosslinked collagen in the ECM. Our study is the first to validate direct regulation of LOX and LOXL2 by the miR-200/ZEB1 axis, defines a novel mechanism driving tumor metastasis, delineates collagen as a prognostic marker, and identifies LOXL2 as a potential therapeutic target against tumor progression.

The miR-200 family and the miR-183~96~182 cluster target Foxf2 to inhibit invasion and metastasis in lung cancers.

Metastatic lung cancer is one of the most lethal forms of cancer and molecular pathways driving metastasis are still not clearly elucidated. Metastatic cancer cells undergo an epithelial-mesenchymal transition (EMT) where they lose their epithelial properties and acquire a migratory and invasive phenotype. Here we identify that the expression of microRNAs from the miR-200 family and the miR-183~96~182 cluster are significantly co-repressed in non-small cell lung cancer cell lines and primary tumors from multiple TCGA dataset with high EMT scores. Ectopic expression of the miR-183~96~182 cluster inhibited cancer cell migration and invasion, whereas its expression was tightly modulated by miR-200. We identified Foxf2 as a common, novel and direct target of both these microRNA families. Foxf2 expression tightly correlates with the transcription factor Zeb1 and is elevated in mesenchymal-like metastatic lung cancer cells. Foxf2 expression induced robust EMT, migration, invasion and metastasis in lung cancer cells, whereas Foxf2 inhibition significantly repressed these phenotypes. We also demonstrated that Foxf2 transcriptionally represses E-cadherin and miR-200, independent of Zeb1, to form a double-negative feedback loop. We, therefore, identified a novel mechanism whereby the miR-200 family and the miR-183~96~182 cluster inhibit lung cancer invasion and metastasis by targeting Foxf2.

Eradication of endotracheal tube biofilm by nebulised gentamicin.

OBJECTIVE: To compare the efficacy of gentamicin, nebulised via the endotracheal tube (ET), with that of parenteral cefotaxime or parenteral cefuroxime in preventing the formation of ET biofilm. SETTING: General intensive care units in two university teaching hospitals. DESIGN: The microbiology of ET biofilm from 36 ICU patients eligible to receive antibiotic prophylaxis was examined. Peak and trough tracheal concentrations of gentamicin, cefotaxime or cefuroxime were measured in each patient group, on the 2nd day of intubation. PATIENTS: Twelve patients received gentamicin (80 mg) nebulised in 4 ml normal saline every 8 h, 12 cefotaxime (1 g, 12 hourly) and 12 cefuroxime (750 mg, 8 hourly). Prophylaxis was continued for the duration of intubation. MEASUREMENTS AND RESULTS: Samples of tracheal secretions were taken on the 2nd day of ventilation for determination of antibiotic concentrations. Following extubation, ETs were examined for the presence of biofilm. Pathogens considered to be common aetiological agents for VAP included Staphylococcus aureus, enterococci, Enterobacteriaceae and pseudomonads. While microbial biofilm was found on all ETs from the cephalosporin group, microbial biofilm of these micro-organisms was found on 7 of the 12 ET tubes from patients receiving cefotaxime [ S. aureus (4), pseudomonads (1), Enterobacteriaceae (1), enterococcus (1)] and 8 of the 12 ET tubes from patients receiving cefuroxime [Enterobacteriaceae (6), P. aeruginosa (1) and enterococcus (1)]. While microbial biofilm was observed on five ETs from patients receiving nebulised gentamicin, none of these were from pathogens for ventilator-associated pneumonia (VAP). Tracheal concentrations of both cephalosporins were lower than those needed to inhibit the growth of pathogens recovered from ET tube biofilm. The median (and range) concentrations for cefotaxime were 0.90 (<0.23-1.31) mg/l and 0.28 (<0.23-0.58) mg/l for 2 h post-dose and trough samples, respectively. Two hours post-dose concentrations of cefuroxime (median and range) were 0.40 (0.34-0.83) mg/l, with trough concentrations of 0.35 (<0.22-0.47) mg/l. Tracheal concentrations (median and range) of gentamicin measured 1 h post-nebulisation were 790 (352-->1250) mg/l and then, before the next dose, were 436 (250-1000) mg/l. CONCLUSION: Nebulised gentamicin attained high concentrations in the ET lumen and was more effective in preventing the formation of biofilm than either parenterally administered cephalosporin and therefore may be effective in preventing this complication of mechanical ventilation.

Implications of endotracheal tube biofilm for ventilator-associated pneumonia.

OBJECTIVE: To determine the relationship between, and antibiotic resistance of, endotracheal tube (ET) biofilm and pulmonary pathogens in ventilator-associated pneumonia (VAP). SETTING: General intensive care units in two university teaching hospitals. DESIGN: The microbiology of ET biofilm and tracheal samples from patients with and without VAP were compared. For individual patients, matching pairs of pathogens were confirmed as identical and characterised for antibiotic susceptibility. PATIENTS: 40 intensive care unit patients - 20 with VAP, 20 without VAP as control. The duration of intubation (median and range) was 6.5 days (3-17) and 5 days (2-10), respectively. MEASUREMENTS AND RESULTS: Samples of tracheal secretions were taken during ventilation for bacteriological culture. Following extubation, ETs were examined for the presence of biofilm. Isolates of high pathogenic potential included Staphylococcus aureus, enterococci, Enterobacteriaceae, pseudomonads and Candida spp. Where the same microorganism was found on tracheal and ET samples by phenotyping, these were confirmed as identical by genotyping and characterised for antibiotic susceptibility in both the free floating and biofilm forms. Seventy per cent of patients with VAP had identical pathogens isolated from both ET biofilm and tracheal secretions. No pairing of pathogens was observed in control patients (p < 0.005). Susceptibility data for these pairs show that the ET acts as a reservoir for infecting microorganisms which exhibit significantly greater antibiotic resistance than their tracheal counterparts. CONCLUSION: This investigation provides further evidence for the role of ET biofilm in VAP. The difficulty in eradicating an established microbial biofilm using antibiotics implies that increased attention must be directed towards modification of the ET to prevent or substantially reduce biofilm formation.

Methods for assessing the public health impact of outflows from combined sewer systems.

OBJECTIVES: Approximately 1,100 communities in the United States have combined sewer and stormwater systems whose capacity may be exceeded during moderate or heavy rainfall. Outflows may occur that can deposit water with varying concentrations of the components of sewage onto public areas, where contact with residents or workers is possible, potentially resulting in a range of adverse health effects. This study proposes and applies three analytic methods to evaluate the impact of such outflows on public health. METHODS: The work attendance records of 449 U.S Postal Service letter carriers in Sacramento, CA, were reviewed to determine the frequency of sick leave use (as a surrogate measure of illness) in relationship to rainfall and potential exposure to sewage-contaminated outflows in two distinct groups of letter carriers from October 1, 1992, through April 30, 1993. Rainfall was a surrogate measure of outflows from the combined sewer and stormwater system because no information existed about the extent of exposure of these (or any other) workers. One group of letter carriers delivered mail exclusively within an area served by the combined sewer and stormwater collection system; the second group delivered mail exclusively outside this area where sewage and stormwater collection are separated. The first approach to the assessment of the data was a description of the temporal relationship between rainfall patterns and absentee rates in the two groups of workers. The second approach used logistic regression modelling with varying lags between rainfall and sick leave usage. The third approach used Poisson regression analysis of the entire study period to examine the differential impact of rainfall on the two groups. RESULTS: The descriptive analyses detected no relationship between rainfall and sick leave use. The logistic regression analyses detected evidence (as measured by the interaction coefficient in logistic models) of an increased use of sick leave by the letter carriers within the Combined System area at lag periods of one, four, and five days after rainfall. These estimates were not, however, statistically significant (p > 0.05). The Poisson regression analysis showed no evidence of a differential impact of rainfall on the two groups (incidence rate ratio = 1.19 in both groups for periods of rain versus no rain). CONCLUSIONS: These three methods can be used to investigate the public health impact of combined system outflows. Ideally, however, these approaches would be applied to prospectively collected surveillance data that would rely upon direct measurements of exposure and illness, rather than surrogate variables.

Structure-activity relationships for antiplasmodial activity among 7-substituted 4-aminoquinolines.

Aminoquinolines (AQs) with diaminoalkane side chains (-HNRNEt2) shorter or longer than the isopentyl side chain [-HNCHMe(CH2)3NEt2] of chloroquine are active against both chloroquine-susceptible and -resistant Plasmodium falciparum. (De, D.; et al. Am. J. Trop. Med. Hyg. 1996, 55, 579-583). In the studies reported here, we examined structure-activity relationships (SARs) among AQs with different N, N-diethyldiaminoalkane side chains and different substituents at the 7-position occupied by Cl in chloroquine. 7-Iodo- and 7-bromo-AQs with diaminoalkane side chains [-HN(CH2)2NEt2, -HN(CH2)3NEt2, or -HNCHMeCH2NEt2] were as active as the corresponding 7-chloro-AQs against both chloroquine-susceptible and -resistant P. falciparum (IC50s of 3-12 nM). In contrast, with one exception, 7-fluoro-AQs and 7-trifluoromethyl-AQs were less active against chloroquine-susceptible P. falciparum (IC50s of 15-50 nM) and substantially less active against chloroquine-resistant P. falciparum (IC50s of 18-500 nM). Furthermore, most 7-OMe-AQs were inactive against both chloroquine-susceptible (IC50s of 17-150 nM) and -resistant P. falciparum (IC50s of 90-3000 nM).

Thermodilution measurement of cardiac output in patients with low output: room-temperature versus iced injectate.

BACKGROUND: Measurements of cardiac output with the thermodilution technique add to data for clinical decision making and therefore must be valid and reliable. However, the results of studies on the accuracy of values obtained with room-temperature and iced injectates, especially in patients with high or low cardiac output, have been conflicting. OBJECTIVE: To determine the effect of the temperature of the injectate (iced or room temperature) on cardiac output values obtained with the thermodilution technique in critically ill adults with known low cardiac output. METHODS: A convenience sample of 50 subjects (41 men and 9 women) who had a cardiac index of less than 2.5 (calculated as cardiac output in liters per minute divided by body surface area in square meters) before the study had cardiac output measured by using a closed system and manual injections of room-temperature and iced injectates. RESULTS: A paired t test indicated no significant difference between iced and room-temperature injectates for cardiac output (iced, 3.62 L/min; room temperature, 3.71 L/min; t = 0.99; P = .327) and cardiac index (iced, 1.95; room temperature, 1.99; t = 0.71; P = .482). CONCLUSION: The findings support the practice of using room-temperature injectate to measure cardiac output in patients with low cardiac output.

The urease-catalyzed hydrolysis of thiourea and thioacetamide.

Jack bean urease catalyzes the hydrolysis of thiourea with a second-order rate constant (kcat/Km) of 1.6 (+/- 0.2) x 10(-3) M-1 S-1 at pH7, 25 degrees C. This value is lower than that for urea by a factor of 3 x 10(8). The corresponding substitution of S for O in acetamide reduces the kcat/Km value by only a factor of 33. This greater reactivity of the oxo compounds than of the corresponding thiono compounds, and the tighter binding of urea (Ks = 2.9 mM) than of either the guanidinium ion (Ki = 30 mM) or thiourea (Ki = 70 mM), suggests that the substrate chalcogen (S or O) is more likely to be stabilized in the transition state by coordination to the enzyme via a neutral hydrogen-bond donor (i.e., Brønsted acid catalysis) than by coordination via one of the active-site nickel ions (i.e., Lewis acid catalysis).

Isolation of a previously unidentified polysaccharide (MAR-10) from Hyssop officinalis that exhibits strong activity against human immunodeficiency virus type 1.

A polysaccharide (MAR-10) was isolated from the aqueous extract of the plant Hyssop officinalis and examined for its activity against HIV-1 (SF strain) in HUT78 T cell line and primary cultures of peripheral blood mononuclear cells. MAR-10, in a concentration-dependent manner, inhibited HIV-1 replication as demonstrated by the inhibition of HIV-1 p24 antigen and syncytia formation. Furthermore, MAR-10 had no significant direct toxicity or effect on lymphocyte functions or CD4+ and CD8+ T cell counts. In addition, MAR-10 has broad spectrum anti-glycosidase activity. Our study demonstrates that MAR-10 contains strong anti-HIV-1 activity that may be useful in the treatment of patients with HIV-1 infection.

Increased levels of laminin in ascitic fluid of patients with ovarian cancer.

Laminin is a component of the extracellular matrix and is associated with tumor cell metastasis. Present studies show that the ovarian cancer cell lines produce significant amounts of laminin (54-140 ng/ml) in culture. Since ovarian cancer is associated with ascites production, laminin levels were then determined in ascites and serum. The results indicate that the ascites from patients with serous adenocarcinoma of the ovary had higher levels of laminin than the normal peritoneal fluid (P < 0.0001). However, the serum levels of laminin did not differ significantly between the control population and ovarian cancer patients.

Purification of class I medullipins from the venous effluent of isolated normal kidneys perfused under high pressure with saline.

Medullipin I (Med I) is a vasodepressor prohormone which is continuously elaborated into the renal venous effluent (RVE) of isolated rat kidneys perfused under high pressure. We have improved the yield of Med I by substituting saline for the albumin perfusate previously reported; and considerably improved refinement by directly fractionating the crude lipid extract of the RVE with high pressure liquid chromatography. The results show that Med I, as defined by previous physiologic and pharmacologic criteria, is not a single molecule. The 3 Class I medullipins described here are distinguished by subtle or overt differences in polarity and biologic activity.

Secretion of medullipin I by the kidney involves the cytochrome P-450 enzyme system.

OBJECTIVE: To determine whether secretion of medullipin I by the kidney is dependent on the cytochrome P-450 enzyme system in Sprague-Dawley and spontaneously hypertensive rats (SHR). METHODS: Isolated kidneys from Sprague-Dawley rats were perfused with 5% human albumin gassed with 95% O2 and 5% CO2 at 185 mmHg. The resultant renal venous effluent was tested in the SHR for medullipin I-type vasodepressor activity. The kidneys were then treated with ketoconazole, and inhibitor of the cytochrome P-450 enzyme system. After rinsing with 50 ml saline, the last 10 ml of which was saved for a control test (see below), the kidneys were reperfused with 50 ml human albumin and the resultant renal venous effluent was tested for vasodepressor activity. One milliliter of the saline rinse was administered to the SHR and the preketoconazole renal venous effluent was administered after 15 min. The medullipin I-type vasodepression occurred. Thus, inhibition of vasodepression after ketoconazole treatment was not due to residual ketoconazole in the post-treatment renal venous effluent. RESULTS: Treatment of isolated kidneys with ketoconazole prevented secretion of medullipin I which had been induced by 5% human albumin. CONCLUSION: The cytochrome P-450 enzyme system is involved in two major metabolic steps of the medullipin system: synthesis of medullipin I by the kidney and conversion of medullipin I to medullipin II by the liver as shown previously.

Lymph node yield from laparoscopic lymphadenectomy in cervical cancer: a comparative study.

Pretreatment surgical staging in cervical cancer has been studied extensively but remains controversial because a surgical procedure is required and the information gained may benefit only a small portion of the patients staged. Pelvic and paraaortic laparoscopic lymphadenectomies have been successfully performed in animal models and humans. Little information regarding the validity of the procedure in patients who have had subsequent laparotomy exists. In this series, we report our preliminary experience in 12 patients who underwent laparoscopic lymphadenectomy and then laparotomy. Overall, 377 pelvic nodes were removed, with 282 (75%) obtained at laparoscopy. The average number of pelvic nodes removed at laparoscopy was 23.5 (range 7-33). Two patients had positive pelvic nodes. No patient with negative nodes at laparoscopy had positive nodes at laparotomy. When studied in chronological order, the lymph node yield from our second 6 patients was much improved over our first 6 patients, 85% versus 63% (P < 0.005). Laparoscopy also proved to be a better predictor of lymph node spread than computed tomography. Two patients also had right-sided paraaortic lymphadenectomies, yielding 8 and 5 nodes. No additional right-sided paraaortic nodes were detected at laparotomy for either patient. In this preliminary series, laparoscopic lymphadenectomy appears to be a feasible procedure for surgical staging of cervical cancer. The yield of pelvic lymph nodes is adequate and improved with experience. Most importantly, no positive lymph nodes were missed by laparoscopy. The indications for operative laparoscopy have expanded rapidly. Gynecologic oncologists performing this procedure should be involved in prospective studies of this technique to set the standards and indications of this new technology.

Transvaginal color flow Doppler sonography in the assessment of gestational trophoblastic disease.

The aim of this study was to evaluate the blood flow characteristics of the uterine artery and intratumoral vessels in patients with GTD. Twelve patients with GTD were evaluated with TVS, and 11 also had CFD sonography performed. Spectral analysis of both uterine artery and samples intratumoral and intramyometrial vessels revealed systolic frequencies and PI that were significantly higher in the uterine artery than in sampled intratumoral vessels (P < 0.05). Uterine artery PI correlated significantly with age (P = 0.043), uterine size (P = 0.003), and beta-HCG titer (P = 0.03). Intratumoral PI correlated significantly with uterine size (P = 0.05). Intratumoral PI did not correlate with patient age, the shape or orientation of the uterus, presence or absence of subendometrial halo, endometrial thickness or echogenicity, or impression of myometrial invasion. Regression analysis of beta-HCG titers on uterine artery and intratumoral PI revealed a linear association. TVS and color flow Doppler sonography are useful in the assessment of patients with GTD. The PI is strongly associated with prognosis and correlates with beta-HCG titers.

Lipomedullipinoma: a source of hypermedullipinemia.

Previously we reported a case of persistent hypotension associated with hypermedullipinemia (Blood Pressure 1992; 1:138-148). The hypermedullipinemia appeared to result from the autonomous secretion of medullipin I (Med I) by renomedullary interstitial cells (RIC's) in the patient's remaining endstage kidney. The patient subsequently died. At autopsy, the remaining kidney contained a yellow mass (1 x 1 x 0.5 cm) consisting of adipocytes and RIC's, termed a lipomedullipinoma. This mass was extracted and chromatographed by procedures known to yield Med I. Med I was identified following these procedures. Renal tissue outside the yellow mass failed to yield Med I. It appears that the hypermedullipinemia of this case resulted from autonomous, hypersecretion of Med I by the lipomedullipinoma.

Phosphonate inhibitors of glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase.

Several bisphosphonates were examined as inhibitors of yeast GPD (glyceraldehyde-3-phosphate dehydrogenase, EC 1.2.1.12) and PGK (phosphoglycerate kinase, EC 2.7.2.3). The phosphonomethyl analog of 2-deoxy-1,3-bisphosphoglycerate (i.e., 2-oxo-1,5-bisphosphonopentane, 2-oxo-PC5P) is a good inhibitor of PGK (Ki = 0.2 +/- 0.08 mM at pH 8.5, 27 degrees C) and a poor inhibitor of GPD (Ki = 20 +/- 1 mM, pH 8.5). The shorter, butane, analog (2-oxo-PC4P) binds more tightly to PGK (Ki = 84 +/- 6 microM), and about equally well to GPD, as does 2-oxo-PC5P. The 2-oxo-bisphosphonates bind to PGK more tightly (by approx. 4 kJ/mol) than do the corresponding non-carbonyl analogues (1,4-bisphosphonobutane and 1,5-bisphosphonopentane).