Methane emissions from cattle

Increasing atmospheric concentrations of methane have led scientists to examine its sources of origin. Ruminant livestock can produce 250 to 500 L of methane per day. This level of production results in estimates of the contribution by cattle to global warming that may occur in the next 50 to 100 yr to be a little less than 2%. Many factors influence methane emissions from cattle and include the following: level of feed intake, type of carbohydrate in the diet, feed processing, addition of lipids or ionophores to the diet, and alterations in the ruminal microflora. Manipulation of these factors can reduce methane emissions from cattle. Many techniques exist to quantify methane emissions from individual or groups of animals. Enclosure techniques are precise but require trained animals and may limit animal movement. Isotopic and nonisotopic tracer techniques may also be used effectively. Prediction equations based on fermentation balance or feed characteristics have been used to estimate methane production. These equations are useful, but the assumptions and conditions that must be met for each equation limit their ability to accurately predict methane production. Methane production from groups of animals can be measured by mass balance, micrometeorological, or tracer methods. These techniques can measure methane emissions from animals in either indoor or outdoor enclosures. Use of these techniques and knowledge of the factors that impact methane production can result in the development of mitigation strategies to reduce methane losses by cattle. Implementation of these strategies should result in enhanced animal productivity and decreased contributions by cattle to the atmospheric methane budget.

Reduction by granulocyte colony-stimulating factor of fever and neutropenia induced by chemotherapy in patients with small-cell lung cancer

BACKGROUND

Neutropenia and infection are major dose-limiting side effects of chemotherapy. Previous studies have suggested that recombinant methionyl granulocyte colony-stimulating factor (G-CSF) can reduce chemotherapy-related neutropenia in patients with cancer. We conducted a randomized clinical trial to test this hypothesis and the clinical implications.

METHODS

Patients with small-cell lung cancer were enrolled in a multicenter, randomized, double-blind, placebo-controlled trial of recombinant methionyl G-CSF to study the incidence of infection as manifested by fever with neutropenia (absolute neutrophil count, less than 1.0 x 10(9) per liter, with a temperature greater than or equal to 38.2 degrees C) resulting from up to six cycles of chemotherapy with cyclophosphamide, doxorubicin, and etoposide. The patients were randomly assigned to receive either placebo or G-CSF, with treatment beginning on day 4 and continuing through day 17 of a 21-day cycle.

RESULTS

The safety of the study treatment could be evaluated in 207 of the 211 patients assigned to either drug, and its efficacy in 199. At least one episode of fever with neutropenia occurred in 77 percent of the placebo group, as compared with 40 percent of the G-CSF group (P less than 0.001). Over all cycles of chemotherapy, the median duration of grade IV neutropenia (absolute neutrophil count, less than 0.5 x 10(9) per liter) was six days with placebo as compared with one day with G-CSF. During cycles of blinded treatment, the number of days of treatment with intravenous antibiotics, the number of days of hospitalization, and the incidence of confirmed infections were reduced by approximately 50 percent when G-CSF was given, as compared with placebo. Mild-to-moderate medullary bone pain occurred in 20 percent of the patients receiving G-CSF.

CONCLUSIONS

The use of G-CSF as an adjunct to chemotherapy in patients with small-cell cancer of the lung was well tolerated and led to reductions in the incidence of fever with neutropenia and culture-confirmed infections; in the incidence, duration, and severity of grade IV neutropenia; and in the total number of days of treatment with intravenous antibiotics and days of hospitalization.

Large-scale discovery of novel genetic causes of developmental disorders

Despite three decades of successful, predominantly phenotype-driven discovery of the genetic causes of monogenic disorders, up to half of children with severe developmental disorders of probable genetic origin remain without a genetic diagnosis. Particularly challenging are those disorders rare enough to have eluded recognition as a discrete clinical entity, those with highly variable clinical manifestations, and those that are difficult to distinguish from other, very similar, disorders. Here we demonstrate the power of using an unbiased genotype-driven approach to identify subsets of patients with similar disorders. By studying 1,133 children with severe, undiagnosed developmental disorders, and their parents, using a combination of exome sequencing and array-based detection of chromosomal rearrangements, we discovered 12 novel genes associated with developmental disorders. These newly implicated genes increase by 10% (from 28% to 31%) the proportion of children that could be diagnosed. Clustering of missense mutations in six of these newly implicated genes suggests that normal development is being perturbed by an activating or dominant-negative mechanism. Our findings demonstrate the value of adopting a comprehensive strategy, both genome-wide and nationwide, to elucidate the underlying causes of rare genetic disorders.

Characterization of circulating T cells specific for tumor-associated antigens in melanoma patients

We identified circulating CD8+ T-cell populations specific for the tumor-associated antigens (TAAs) MART-1 (27-35) or tyrosinase (368-376) in six of eleven patients with metastatic melanoma using peptide/HLA-A*0201 tetramers. These TAA-specific populations were of two phenotypically distinct types: one, typical for memory/effector T cells; the other, a previously undescribed phenotype expressing both naive and effector cell markers. This latter type represented more than 2% of the total CD8+ T cells in one patient, permitting detailed phenotypic and functional analysis. Although these cells have many of the hallmarks of effector T cells, they were functionally unresponsive, unable to directly lyse melanoma target cells or produce cytokines in response to mitogens. In contrast, CD8+ T cells from the same patient were able to lyse EBV-pulsed target cells and showed robust allogeneic responses. Thus, the clonally expanded TAA-specific population seems to have been selectively rendered anergic in vivo. Peptide stimulation of the TAA-specific T-cell populations in other patients failed to induce substantial upregulation of CD69 expression, indicating that these cells may also have functional defects, leading to blunted activation responses. These data demonstrate that systemic TAA-specific T-cell responses can develop de novo in cancer patients, but that antigen-specific unresponsiveness may explain why such cells are unable to control tumor growth.

The stroke impact scale version 2.0. Evaluation of reliability, validity, and sensitivity to change

BACKGROUND AND PURPOSE

To be useful for clinical research, an outcome measure must be feasible to administer and have sound psychometric attributes, including reliability, validity, and sensitivity to change. This study characterizes the psychometric properties of the Stroke Impact Scale (SIS) Version 2.0.

METHODS

Version 2.0 of the SIS is a self-report measure that includes 64 items and assesses 8 domains (strength, hand function, ADL/IADL, mobility, communication, emotion, memory and thinking, and participation). Subjects with mild and moderate strokes completed the SIS at 1 month (n=91), at 3 months (n=80), and at 6 months after stroke (n=69). Twenty-five subjects had a replicate administration of the SIS 1 week after the 3-month or 6-month test. We evaluated internal consistency and test-retest reliability. The validity of the SIS domains was examined by comparing the SIS to existing stroke measures and by comparing differences in SIS scores across Rankin scale levels. The mixed model procedure was used to evaluate responsiveness of the SIS domain scores to change.

RESULTS

Each of the 8 domains met or approached the standard of 0.9 alpha-coefficient for comparing the same patients across time. The intraclass correlation coefficients for test-retest reliability of SIS domains ranged from 0.70 to 0.92, except for the emotion domain (0.57). When the domains were compared with established outcome measures, the correlations were moderate to strong (0.44 to 0.84). The participation domain was most strongly associated with SF-36 social role function. SIS domain scores discriminated across 4 Rankin levels. SIS domains are responsive to change due to ongoing recovery. Responsiveness to change is affected by stroke severity and time since stroke.

CONCLUSIONS

This new, stroke-specific outcome measure is reliable, valid, and sensitive to change. We are optimistic about the utility of measure. More studies are required to evaluate the SIS in larger and more heterogeneous populations and to evaluate the feasibility and validity of proxy responses for the most severely impaired patients.

Gene expression analysis by massively parallel signature sequencing (MPSS) on microbead arrays

We describe a novel sequencing approach that combines non-gel-based signature sequencing with in vitro cloning of millions of templates on separate 5 microm diameter microbeads. After constructing a microbead library of DNA templates by in vitro cloning, we assembled a planar array of a million template-containing microbeads in a flow cell at a density greater than 3x10(6) microbeads/cm2. Sequences of the free ends of the cloned templates on each microbead were then simultaneously analyzed using a fluorescence-based signature sequencing method that does not require DNA fragment separation. Signature sequences of 16-20 bases were obtained by repeated cycles of enzymatic cleavage with a type IIs restriction endonuclease, adaptor ligation, and sequence interrogation by encoded hybridization probes. The approach was validated by sequencing over 269,000 signatures from two cDNA libraries constructed from a fully sequenced strain of Saccharomyces cerevisiae, and by measuring gene expression levels in the human cell line THP-1. The approach provides an unprecedented depth of analysis permitting application of powerful statistical techniques for discovery of functional relationships among genes, whether known or unknown beforehand, or whether expressed at high or very low levels.

Expression and structure of the human NGF receptor

The nucleotide sequence for the human nerve growth factor (NGF) receptor has been determined. The 3.8 kb receptor mRNA encodes a 427 amino acid protein containing a 28 amino acid signal peptide, an extracellular domain containing four 40 amino acid repeats with six cysteine residues at conserved positions followed by a serine/threonine-rich region, a single transmembrane domain, and a 155 amino acid cytoplasmic domain. The sequence of the extracellular domain of the NGF receptor predicts a highly ordered structure containing a negatively charged region that may serve as the ligand-binding site. This domain is conserved through evolution. Transfection of a full-length cDNA in mouse fibroblasts results in stable expression of NGF receptors that are recognized by monoclonal antibodies to the human NGF receptor and that bind [125I]NGF.

Herpes simplex virus turns off the TAP to evade host immunity

Many viruses have evolved mechanisms to avoid detection by the host immune system. Herpes simplex virus (HSV) expresses an immediate early protein, ICP47, which blocks presentation of viral peptides to MHC class I-restricted cells. The properties of the newly synthesized class I molecules in HSV-infected cells resemble those of cell lines deficient in the transporter associated with antigen processing (TAP) in that class I molecules are retained in the endoplasmic reticulum, and the heavy chain and beta 2-microglobulin subunits dissociate in detergent extracts but the complex can be stabilized by peptides. We show here that ICP47 binds to TAP and prevents peptide translocation into the endoplasmic reticulum.

A prospective study of dengue infections in Bangkok

Dengue infections were prospectively studied among 4- to 16-year-old students at a Bangkok school. Blood samples were obtained from 1,757 students in June 1980, before the dengue season, and in January 1981, after the season, and tested for dengue antibodies by the hemagglutination inhibition method. Classrooms were monitored daily for school absences. Fifty percent of the children had antibodies to, and were presumably immune to, at least 1 dengue serotype by the age of 7 years. Most (90/103, 87%) students who became infected by dengue viruses during the study period were either asymptomatic or minimally symptomatic (absent only 1 day). Most (7/13, 53%) of the symptomatic dengue infections (absent with fever for greater than or equal to 2 days) were clinically recognized as cases of dengue hemorrhagic fever which required hospitalization. None of 47 primary dengue infections required hospitalization, whereas 7 of 56 secondary infections did (P = 0.012). Preexistent dengue immunity, as detected by conventional serologic techniques, was a significant (odds ratio greater than or equal to 6.5) risk factor for development of dengue hemorrhagic fever.

Purification and complementary DNA cloning of a receptor for basic fibroblast growth factor

Basic fibroblast growth factor (bFGF) participates in many processes including early developmental events, angiogenesis, wound healing, and maintenance of neuronal cell viability. A 130-kilodalton protein was isolated on the basis of its ability to specifically bind to bFGF. A complementary DNA clone was isolated with an oligonucleotide probe corresponding to determined amino acid sequences of tryptic peptide fragments of the purified protein. The putative bFGF receptor encoded by this complementary DNA is a transmembrane protein that contains three extracellular immunoglobulin-like domains, an unusual acidic region, and an intracellular tyrosine kinase domain. These domains are arranged in a pattern that is different from that of any growth factor receptor described.

Radiation Therapy Oncology Group (RTOG) 88-08 and Eastern Cooperative Oncology Group (ECOG) 4588: preliminary results of a phase III trial in regionally advanced, unresectable non-small-cell lung cancer

BACKGROUND

Regionally advanced, surgically unresectable non-small-cell lung cancer represents a disease with an extremely poor prognosis. External-beam irradiation to the primary tumor and regional lymphatics is generally accepted as standard therapy. The use of more aggressive radiation regimens and the addition of cytotoxic chemotherapy to radiotherapy have yielded conflicting results. Recently, however, results from clinical trials using innovative irradiation delivery techniques or chemotherapy before irradiation have indicated that patients treated with protocols that incorporate these modifications may have higher survival rates than patients receiving standard radiation therapy.

PURPOSE

On the basis of these results, the Radiation Therapy Oncology Group (RTOG)-Eastern Cooperative Oncology Group (ECOG) elected to conduct a phase III trial comparing the following regimens: 1) standard radiation therapy, 2) induction chemotherapy followed by standard radiation therapy, and 3) twice-daily radiation therapy.

METHODS

Patients with surgically unresectable stage II, IIIA, or IIIB non-small-cell lung cancer were potential candidates. Staging was nonsurgical. Patients were required to have a Karnofsky performance status of 70 or more and weight loss less than 5% for 3 months prior to entry into the trial, to be older than 18 years of age, and to have no metastatic disease. Of the 490 patients registered in the trial, 452 were eligible. The disease in 95% of the patients was stage IIIA or IIIB. More than two thirds of the patients had a Karnofsky performance status of more than 80. Patients were randomly assigned to receive either 60 Gy of radiation therapy delivered at 2 Gy per fraction, 5 days a week, over a 6-week period (standard radiation therapy); induction chemotherapy consisting of cisplatin (100 mg/m2) on days 1 and 29 and 5 mg/m2 vinblastine per week for 5 consecutive weeks beginning on day 1 with cisplatin, followed by standard radiation therapy starting on day 50; or 69.6 Gy delivered at 1.2 Gy per fraction twice daily (hyperfractionated radiation therapy).

RESULTS

Toxicity was acceptable, with four treatment-related deaths. Three patients subsequently died of chronic pulmonary complications. Compliance with protocol treatment was acceptable. One-year survival (%) and median survival (months) were as follows: standard radiation therapy--46%, 11.4 months; chemotherapy plus radiotherapy--60%, 13.8 months; and hyperfractionated radiation therapy--51%, 12.3 months. The chemotherapy plus radiotherapy arm was statistically superior to the other two treatment arms (logrank P = .03).

CONCLUSIONS

In "good-risk" patients with surgically unresectable non-small-cell lung cancer, induction chemotherapy followed by irradiation was superior to hyperfractionated radiation therapy or standard radiation therapy alone, yielding a statistically significant short-term survival advantage.

Constitutive activation of Stat3 signaling abrogates apoptosis in squamous cell carcinogenesis in vivo

Field cancerization predisposes the upper aerodigestive tract mucosa to the formation of multiple primary tumors, when exposed to environmental carcinogens. Up-regulation of epidermal growth factor receptor occurs early in squamous cell carcinogenesis and is critical for the loss of growth control in a variety of human cancers, including head and neck squamous cell carcinomas. In these tumor cells in culture, epidermal growth factor receptor stimulation initiates signaling via persistent activation of selective STAT proteins. To determine the timing of Stat3 activation in head and neck carcinogenesis, we studied the expression and constitutive activation of Stat3 in tumors and normal mucosa from patients with head and neck cancer compared with mucosa from controls without cancer. Stat3 was up-regulated and constitutively activated in both primary human head and neck tumors as well as in normal mucosa from these cancer patients compared with control normal mucosa from patients without cancer. In vivo liposome-mediated gene therapy with a Stat3 antisense plasmid efficiently inhibited Stat3 activation, increased tumor cell apoptosis, and decreased Bcl-x(L) expression in a head and neck xenograft model. These findings provide evidence that constitutively activated Stat3 is an early event in head and neck carcinogenesis that contributes to the loss of growth control by an anti-apoptotic mechanism.

Comparison of survival and quality of life in advanced non-small-cell lung cancer patients treated with two dose levels of paclitaxel combined with cisplatin versus etoposide with cisplatin: results of an Eastern Cooperative Oncology Group trial

PURPOSE

Treatment with cisplatin-based chemotherapy provides a modest survival advantage over supportive care alone in advanced non-small-cell lung cancer (NSCLC). To determine whether a new agent, paclitaxel, would further improve survival in NSCLC, the Eastern Cooperative Oncology Group conducted a randomized trial comparing paclitaxel plus cisplatin to a standard chemotherapy regimen consisting of cisplatin and etoposide.

PATIENTS AND METHODS

The study was carried out by a multi-institutional cooperative group in chemotherapy-naive stage IIIB to IV NSCLC patients randomized to receive paclitaxel plus cisplatin or etoposide plus cisplatin. Paclitaxel was administered at two different dose levels (135 mg/m(2) and 250 mg/m(2)), and etoposide was given at a dose of 100 mg/m(2) daily on days 1 to 3. Each regimen was repeated every 21 days and each included cisplatin (75 mg/m(2)).

RESULTS

The characteristics of the 599 patients were well-balanced across the three treatment groups. Superior survival was observed with the combined paclitaxel regimens (median survival time, 9.9 months; 1-year survival rate, 38.9%) compared with etoposide plus cisplatin (median survival time, 7.6 months; 1-year survival rate, 31.8%; P =. 048). Comparing survival for the two dose levels of paclitaxel revealed no significant difference. The median survival duration for the stage IIIB subgroup was 7.9 months for etoposide plus cisplatin patients versus 13.1 months for all paclitaxel patients (P =.152). For the stage IV subgroup, the median survival time for etoposide plus cisplatin was 7.6 months compared with 8.9 months for paclitaxel (P =.246). With the exceptions of increased granulocytopenia on the low-dose paclitaxel regimen and increased myalgias, neurotoxicity, and, possibly, increased treatment-related cardiac events with high-dose paclitaxel, toxicity was similar across all three arms. Quality of life (QOL) declined significantly over the 6 months. However, QOL scores were not significantly different among the regimens.

CONCLUSION

As a result of these observations, paclitaxel (135 mg/m(2)) combined with cisplatin has replaced etoposide plus cisplatin as the reference regimen in our recently completed phase III trial.

Final results of phase III trial in regionally advanced unresectable non-small cell lung cancer: Radiation Therapy Oncology Group, Eastern Cooperative Oncology Group, and Southwest Oncology Group

STUDY OBJECTIVES

The purpose of this phase III clinical trial was to test whether chemotherapy followed by radiation therapy resulted in superior survival to either hyperfractionated radiation or standard radiation in surgically unresectable non-small cell lung cancer.

DESIGN

Patients were prospectively randomized to 2 months of cisplatin, vinblastine chemotherapy followed by 60 Gy of radiation at 2.0 Gy per fraction or 1.2 Gy per fraction radiation delivered twice daily to a total dose of 69.6 Gy, or 2.0 Gy per fraction of radiation once daily to 60 Gy. Patients were enrolled from January 1989 through January 1992, and followed for a potential minimum period of 5 years.

SETTING

This trial was an intergroup National Cancer Institute-funded trial within the Radiation Therapy Oncology Group, the Eastern Cooperative Oncology Group, and the Southwest Oncology Group.

PATIENTS

Patients with surgically unresectable non-small cell lung cancer, clinical stage II, IIIA, and IIIB, were required to have a Karnofsky Performance Status of > or = 70 and a weight loss of < 5% for 3 months before study entry. Four hundred ninety patients were registered on trial, of which 458 patients were eligible.

CONCLUSION

Overall survival was statistically superior for the patients receiving chemotherapy and radiation vs the other two arms of the study. The twice-daily radiation therapy arm, although better, was not statistically superior in survival for those patients receiving standard radiation. Median survival for standard radiation was 11.4 months; for chemotherapy and irradiation, 13.2 months; and for hyperfractionated irradiation, 12 months. The respective 5-year survivals were 5% for standard radiation therapy, 8% for chemotherapy followed by radiation therapy, and 6% for hyperfractionated irradiation.

Pyelonephritogenic Escherichia coli and killing of cultured human renal proximal tubular epithelial cells: role of hemolysin in some strains

Acute pyelonephritis, a complication of Escherichia coli bacteriuria, must represent a bacterial invasion through the kidney epithelium. To study this process, we overlaid bacterial suspensions onto monolayers of cultured human kidney proximal tubular epithelial cells and measured cytotoxicity by release of lactate dehydrogenase (LDH). Thirty-four isolates cultured from patients with acute pyelonephritis were screened for the ability to cause pyelonephritis in CBA mice by transurethral challenge. The eight most virulent strains (greater than or equal to 70% of mice challenged developed greater than or equal to 10(3) CFU/g of kidney after 48 h) were selected for study. Each strain displayed mannose-resistant hemagglutination of human O erythrocytes; three strains were phenotypically and genotypically hemolytic. Pyelonephritogenic strains were significantly more cytotoxic (30.1 +/- 9.5% LDH release after 18 h) than eight fecal control strains (13.5 +/- 11.5% LDH release; P = 0.0068). We selected the most cytotoxic strain, CFT073, for further study. Sterile filtrate from this hemolytic strain was significantly more cytotoxic than was the filtrate of the fecal control strain, FN414. Transposon mutagenesis of CFT073 with TnphoA abolished hemolytic activity and cytotoxicity by both whole cells and sterile filtrate. Southern blot analysis revealed that the Tnphoa insertion mapped to the E. coli chromosomal hly determinant within a 12-kilobase SalI restriction fragment. Transformation of a nonhemolytic strain, CPZ005 with plasmid pSF4000, which carries a cloned hemolysin determinant, resulted in highly elevated cytotoxicity. Light micrographs of proximal tubular epithelial cell cultures demonstrated cell damage by pyelonephritogenic strains that was not induced by a fecal strain or the hemolysin-deficient mutant. Results indicate that pyelonephritogenic E. coli strains are more frequently cytotoxic for a putative target, that is, human renal tubular epithelium, than are fecal isolates. Hemolysin, in some strains, is apparently responsible for this cytotoxicity.

Structured exercise improves physical functioning in women with stages I and II breast cancer: results of a randomized controlled trial

PURPOSE

Self-directed and supervised exercise were compared with usual care in a clinical trial designed to evaluate the effect of structured exercise on physical functioning and other dimensions of health-related quality of life in women with stages I and II breast cancer.

PATIENTS AND METHODS

One hundred twenty-three women with stages I and II breast cancer completed baseline evaluations of generic and disease- and site-specific health-related quality of life, aerobic capacity, and body weight. Participants were randomly allocated to one of three intervention groups: usual care (control group), self-directed exercise, or supervised exercise. Quality of life, aerobic capacity, and body weight measures were repeated at 26 weeks. The primary outcome was the change in the Short Form-36 physical functioning scale between baseline and 26 weeks.

RESULTS

Physical functioning in the control group decreased by 4.1 points, whereas it increased by 5.7 points and 2.2 points in the self-directed and supervised exercise groups, respectively (P =.04). Post hoc analysis showed a moderately large (and clinically important) difference between the self-directed and control groups (9.8 points; P =.01) and a more modest difference between the supervised and control groups (6.3 points; P =.09). No significant differences between groups were observed for changes in quality of life scores. In a secondary analysis of participants stratified by type of adjuvant therapy, supervised exercise improved aerobic capacity (+3.5 mL/kg/min; P =.01) and reduced body weight (-4.8 kg; P <.05) compared with usual care only in participants not receiving chemotherapy.

CONCLUSION

Physical exercise can blunt some of the negative side effects of breast cancer treatment, including reduced physical functioning. Self-directed exercise is an effective way to improve physical functioning compared with usual care. In participants not receiving chemotherapy, supervised exercise may increase aerobic capacity and reduce body weight compared with usual care.

Abnormal noradrenergic function in posttraumatic stress disorder

To evaluate possible abnormal noradrenergic neuronal regulation in patients with posttraumatic stress disorder (PTSD), the behavioral, biochemical, and cardiovascular effects of intravenous yohimbine hydrochloride (0.4 mg/kg) were determined in 18 healthy male subjects and 20 male patients with PTSD. A subgroup of patients with PTSD were observed to experience yohimbine-induced panic attacks (70% [14/20]) and flashbacks (40% [8/20]), and they had larger yohimbine-induced increases in plasma 3-methoxy-4-hydroxyphenylglycol levels, sitting systolic blood pressure, and heart rate than those in healthy subjects. In addition, in the patients with PTSD, yohimbine induced significant increases in core PTSD symptoms, such as intrusive traumatic thoughts, emotional numbing, and grief. These data were consistent with a large body of preclinical data that indicated that uncontrollable stress produces substantial increases in noradrenergic neuronal function. We discuss the implications of these abnormalities in noradrenergic functional regulation in relation to the long-term neurobiological sequelae of severe uncontrollable stress and the pathophysiological relationship between PTSD and other anxiety disorders, such as panic disorder.

The value of patient-reported adherence to antiretroviral therapy in predicting virologic and immunologic response. California Collaborative Treatment Group

OBJECTIVE

To correlate self-reported antiretroviral adherence with virologic suppression.

DESIGN

Prospective observational study of adherence to therapy nested in a randomized comparative trial of frequent versus infrequent monitoring of plasma HIV RNA.

SETTING

Five university-affiliated HIV clinics.

PATIENTS

A group of 173 HIV-infected patients with a mean baseline CD4 count of 142 x 10(6) cells/l (range 3-515) of whom 164 and 119 completed adherence questionnaires at 2 and 6 months, respectively.

INTERVENTION

Individualized, unrestricted antiretroviral therapy.

MEASUREMENTS

Patients were classified into four groups by adherence to therapy in the previous 4 weeks (< 80%, 80-95%, 95-99%, 100%). Plasma HIV RNA levels and CD4 lymphocyte counts were measured bimonthly.

RESULTS

Recreational drug or alcohol use was associated with decreased adherence, whereas frequency of HIV RNA monitoring, demographic variables, (age, gender, education, and risk group) and stage of disease had no effect. Greater HIV suppression at 6 months was seen across four categories of increasing adherence (P = 0.009 for linear trend). Patients reporting < 80% adherence at 6 months had a 0.2 log10 copies/ml increase in HIV RNA and a loss of 19 x 10(6) CD4 cells/l compared with a 1.1 log10 copies/ml decrease in HIV RNA and an increase of 72 x 10(6) CD4 cells/l in those reporting 100% adherence (P = 0.02).

CONCLUSION

Self-reported poor adherence (< 80%) and drug or alcohol use predicted non-response of HIV RNA at 6 months of antiretroviral therapy.

Prognostic value of tumor "budding" in patients with colorectal cancer

From 1970 to 1985, 663 patients underwent curative resection of colon and rectal adenocarcinomas. All surgical specimens were examined for tumor "budding," defined as small clusters of undifferentiated cancer cells ahead of the invasive front of the lesion. Patients were divided into two groups according to degree of budding: none or mild (BD-1) and moderate or severe (BD-2). BD-1 occurred in 493 patients (74.4 percent), and BD-2 was found in 170 patients (25.6 percent). More severe budding was associated with worse outcome: 71.1 percent of BD-2 patients had recurrence, compared with 20.0 percent of BD-1 patients (P < 0.005). The five-year survival rate was worse in BD-2 than in BD-1 (22.2 percent vs. 70.7 percent; P < 0.001). The 10-year survival rate was also worse in BD-2 than in BD-1 (13.8 percent vs. 50.6 percent; P < 0.001). The incidence of BD-2 rose with the Dukes stage. However, the five-year survival rate of Dukes B patients with BD-2 lesions was worse than that of Dukes C patients with BD-1 cancers (29.1 percent vs. 66.2 percent; P < 0.001). Moreover, there was no difference in five-year survival among BD-1 patients with either Dukes B or C lesions (68.3 percent vs. 66.2 percent). The presence of more severe budding appears to indicate a vigorous biologic activity of colorectal cancer. Thus, meticulous follow-up--and possibly adjuvant chemotherapy--may be beneficial for patients with marked budding, regardless of their Dukes stage.

Isolation of albumin from whole human plasma and fractionation of albumin-depleted plasma

The dye Cibacron Blue F-3-GA was conjugated to Sepharose to provide an affinity column for serum albumin. Passage of whole human plasma through a column of Cibacron Blue-Sepharose results in the removal of approx. 98% of the albumin. The latter can be quantitatively recovered by desorption with NaSCN. Albumin-depleted plasma can be readily resolved into discrete fractions by a combination of conventional biochemical techniques. In particular, the resolution of plasma proteins with properties similar to those of native human plasma albumin can readily be accomplished by ion-exchange chromatography of the Sepharose-dye-treated plasma on DEAE-cellulose.

The growing teratoma syndrome

Six patients with metastatic mixed germ-cell tumors who had been treated successfully with chemotherapy had recurring solitary enlarging masses. Four had enlarging pulmonary masses and two patients had enlarging abdominal masses. Each had the presumed chemotherapy refractory mass surgically resected and was found to have mature teratoma with absence of malignant histologies. The growth in two patients can be attributed to tense and expansile cysts; the remaining four had firm masses. All patients remain free of disease without further therapy at 5, 13, 14, 25, 66, and 108 months. Early recognition of this previously unreported and unusual clinical circumstance of a benign teratoma to grow after chemotherapy will allow for surgical salvage.

Pharmacodynamics of a fluoroquinolone antimicrobial agent in a neutropenic rat model of Pseudomonas sepsis

We examined the impact of dose fractionation and altered MICs on survivorship in a neutropenic rat model of Pseudomonas aeruginosa sepsis employing the new fluoroquinolone antibiotic lomefloxacin. Once-daily administration of a drug dose which produced a high peak concentration/MIC (peak/MIC) ratio (ca. 20/1) produced significantly better survivorship compared with regimens employing the same daily dose but on a more fractionated schedule. The use of a smaller dose, producing lower (< 10/1) peak/MIC ratios, did not show this effect, as once-daily and twice-daily regimens produced equivalent results (the area under the concentration-time curve/MIC ratio was linked to survivorship). Challenge with resistant mutants selected for altered MICs of fluoroquinolones (two and four times the MIC for the parent strain, respectively) resulted in markedly diminished survivorship. Challenge with the parent strain and use of a drug dose which produced a peak/MIC ratio identical to that for animals challenged with the mutant for which the MIC was four times that for the parent strain and treated with the larger drug dose produced survivorship curves which were not different. For this animal model, peak/MIC ratio was linked to survivorship, particularly when high ratios (10/1 to 20/1) were obtained. At lower doses, producing peak/MIC ratios < 10/1, the area under the concentration-time curve relative to the MIC appeared to be most closely linked to outcome. The time that levels in plasma exceeded the MIC did not influence survivorship. The hypothesis most likely to explain these findings is that higher peak/MIC ratios can suppress the parent strain and mutant organisms (gyrA and transport mutants) for which the MIC is higher but limited (no more than eight times that for the parent strain).