Field Evaluation of Insecticides for Control of Cabbage Maggot (Diptera: Anthomyiidae) in Rutabaga in Canada.

At the time of this research, there were only two insecticides registered for control of cabbage maggot, Delia radicum L., in rutabaga in Canada, one of which (diazinon) will be deregistered by 2017, and resistance having been reported in some areas for the other (chlorpyrifos). To screen for chemistries to replace these organophosphates, and obtain efficacy data comparable between key vegetable brassica production areas in Canada, four small plot field studies were conducted concurrently in British Columbia, Saskatchewan, Ontario, and Quebec in 2009. These studies followed standardized protocols for seeding, application of insecticide drenches, sampling and damage assessment, and generally tested the same products. Of the insecticides evaluated, none provided maggot control comparable with the industry standard, chlorpyrifos. However, cyantraniliprole (Cyazypyr 200SC; registered in 2015 as Verimark) applied at 3 g AI (15.0 ml product)/100 m row of seeded rutabagas consistently provided the next highest reduction in % culls, suggesting the efficacy of this chemical may be improved if used at higher rates. The results of these studies are discussed in the context of current literature on D. radicum management in rutabaga. Future management strategies are also discussed, including a transplant plug treatment approach for increasing the dosage per plant and efficacy of chemistries such as Cyazypyr 200SC in the field.

Clinical spectrum of eye malformations in four patients with Mowat-Wilson syndrome.

Mowat-Wilson syndrome (MWS) is a rare genetic syndrome characterized by a specific facial gestalt, intellectual deficiency, Hirschsprung disease and multiple congenital anomalies. Heterozygous mutations or deletions in the zinc finger E-box-binding homeobox2 gene (ZEB2) cause MWS. ZEB2 encodes for Smad-interacting protein 1, a transcriptional co-repressor involved in TGF-beta and BMP pathways and is strongly expressed in early stages of development in mice. Eye abnormalities have rarely been described in patients with this syndrome. Herein, we describe four patients (two males and two females; mean age 7 years) with MWS and eye malformations. Ocular anomalies included, iris/retinal colobomas, atrophy or absence of the optic nerve, hyphema, and deep refraction troubles, sometimes with severe visual consequences. All eye malformations were asymmetric and often unilateral and all eye segments were affected, similarly to the nine MWS cases with ophthalmological malformations previously reported (iris/chorioretinal/optic disc coloboma, optic nerve atrophy, retinal epithelium atrophy, cataract, and korectopia). In human embryo, ZEB2 is expressed in lens and neural retina. Using the present report and data from the literature, we set out to determine whether or not the presence of eye manifestations could be due to specific type or location of mutations. We concluded that the presence of eye malformations, although a rare feature in MWS, should be considered as a part of the clinical spectrum of the condition.

[Persistent foveal retinal detachment after successful rhegmatogenous retinal detachment surgery by scleral buckling]. / Persistance de liquide sous-rétinien maculaire après traitement d'un décollement de rétine rhegmatogène par cryothérapie-indentation.

We report the case of a phakic patient with late visual recovery after successful surgery of macula-off retinal detachment, using the scleral buckling procedure. Visual acuity remained low because of the persistence of subfoveal fluid despite the reattachment of peripheral retina. The amount of subfoveal fluid decreased slowly and final visual acuity finally recovered. We used optical coherence tomography (OCT) to quantify the remaining subfoveal fluid. Persistence of submacular fluid can explain late visual recovery after surgical treatment of retinal detachment.

Trefoil factor family 1, MUC5AC and human leucocyte antigen-DR expression by conjunctival cells in patients with glaucoma treated with chronic drugs: could these markers predict the success of glaucoma surgery?

AIMS: To evaluate conjunctival expression of trefoil factor family (TFF)1, MUC5AC and human leucocyte antigen (HLA)-DR in patients with glaucoma treated with topical drugs, and to determine whether these parameters can predict the outcome of glaucoma surgery. METHODS: 77 conjunctival impression cytology specimens were collected from 77 patients with glaucoma (66 receiving drops with preservative and 11 treated with preservative-free drops) and 43 controls. TFF1, MUC5AC and HLA-DR expression was analysed using flow cytometry. Trabeculectomy was performed in 56 patients; success was defined as an intraocular pressure (IOP) < or =15 mm Hg without any IOP-lowering drug at 6 months. RESULTS: The expression of TFF1, MUC5AC and HLA-DR was significantly higher in patients than in controls (p = 0.01, 0.05 and 0.004, respectively). A higher expression of MUC5AC was found in patients treated with preserved drops than in those receiving unpreserved drops (p = 0.04). A higher MUC5AC expression and a lower HLA-DR expression was observed in successful glaucoma surgeries than in failures. CONCLUSIONS: TFF1 and MUC5AC secretions are probably a response to mild ocular surface changes caused by long-term use of topical treatment. Their increased expression could be a predicting factor of further successful glaucoma surgery.

[Study of ocular surface involvement in diabetic patients]. / Etude des atteintes de la surface oculaire chez les patients diabétiques.

INTRODUCTION: Diabetes mellitus leads to microvascular complications and altered basement membranes, which are partly responsible for ocular complications. Corneal nerve impairment is involved in ocular surface disease as well. We examined the possible relation between ocular surface signs and retinal or neuronal degenerative complications due to diabetes. PATIENTS AND METHODS: Diabetics and control subjects were compared for corneal sensitivity and tear function parameters such as the Schirmer test, tear film break-up time (BUT), and fluorescein and lissamine green stainings. The relation of the duration of the disease, the stage of retinopathy, metabolic control (HbA1c), and diabetic peripheral neuropathy with ocular surface disorders were noted. RESULTS: Twelve healthy patients were compared to 48 diabetics. The Schirmer test value, BUT, and fluorescein and lissamine green impregnations were significantly modified in diabetics compared to controls (p<0.0001), with no relation to the duration of the disease or metabolic control. The mean corneal sensitivity was significantly lower in diabetic patients (p<0.01), diabetics with peripheral neuropathy (p=0.00008), and diabetics with preproliferative retinopathy (p=0.0003). Tear function parameters were more frequently altered in patients presenting preproliferative retinopathy and peripheral neuropathy (p<0.001). CONCLUSIONS: Diabetes can lead to ocular surface impairments with qualitative and quantitative tear disorders, all of which seem to evolve in close relation with retinopathy and peripheral neuropathy. These lacrymal and corneoconjunctival abnormalities, even if not currently mentioned by diabetic patients, can result in severe neurotrophic complications.

[Postoperative acute endophthalmitis: a prospective study. Clinical presentation, management and prognostic factors]. / Etude prospective sur les endophtalmies aiguës postopératoires. Description clinique, prise en charge facteurs de risque.

AIMS: To assess the characteristics and visual outcome of patients with acute postoperative endophthalmitis hospitalized in a referral center. MATERIALS AND METHODS: All patients suspected of having infectious endophthalmitis were included in this study. All patients were treated with the same protocol including at least intravitreal injection of antibiotics and instillation of fortified antibiotics. Symptoms, visual acuity, and slit lamp examination were recorded before treatment, at the end of hospitalization and during clinical follow-up. Treatments and biological results were also reported. For patients developing infectious endophthalmitis after cataract surgery, intraoperative management such as location of the incision, suture or sutureless incision, and material of the intraocular lens were also noted. RESULTS: Forty-one patients were included in the study over 32 months (33 patients after cataract surgery). Intraocular inflammation and a decrease in subjective visual acuity were the most frequently reported findings (90% and 94%, respectively). Ocular pain and conjunctiva injection were less frequently reported (47% and 48%, respectively). Symptoms occurred 5 days after the surgery (median); 56% of patients needed a second intravitreal injection of antibiotics. There was a significant increase in visual acuity during and after hospitalization; median final visual acuity was 4.6/10 (0.34 log MAR = 20/43); 30% of patients had less than 20/200, but 44% more than 20/40. In endophthalmitis following cataract surgery, incisions were corneal in all cases and sutured in 62% of cases. Incisions were temporal in 55% of patients. DISCUSSION: Our results are similar to those previously published for acute endophthalmitis following ocular surgery. Intravitreal antibiotic injection remains the gold standard on the management of acute postoperative endophthalmitis.

[Treating severe dry eye syndromes with autologous serum]. / Traitement des syndromes secs graves par sérum autologue.

BACKGROUND: Dry eye syndrome with tear deficiency can be improved with artificial tears, which can be associated with topical anti-inflammatory agents. Autologous serum can provide the ocular surface with beneficial growth factors and vitamins. PATIENTS AND METHODS: Twenty-one patients suffering from severe dry eye due to Sjögren's syndrome were treated with 20% autologous serum for 2 Months. The Schirmer I test, break-up time, and fluorescein and lissamine green stainings were performed before and after treatment. Subjective complaints such as burning, foreign body sensation, dryness and photophobia were assessed by a questionnaire as well as a face score reflecting the current condition of patients' eyes. RESULTS: Lissamine green and fluorescein scores improved significantly as well as subjective symptoms of burning, foreign body sensation and dryness (p<0.05). The face score was significantly improved. Bacterial culture of serum delivered to the patients all remained negative. DISCUSSION: Autologous serum provides growth factors and vitamins that are useful for an altered ocular surface due to Sjögren's disease. However, some problems still remain: risk of contamination, arbitrary dilution of autologous serum, and a current lack of regulations for use of autologous serum. A close collaboration between ophthalmologists and the Etablissement Français du Sang (French Blood Bank) is mandatory because autologous serum should be considered as a useful tool to treat severe ocular surface disorders. CONCLUSION: The use of autologous serum improved symptoms and objective signs caused by severe Sjögren's syndrome. Currently, a lack of clear regulations prevents its widespread use in severe ocular surface disorders.

[A screening questionnaire for determining risk of Creuzfeldt-Jacob disease transmission during ophthalmic examination]. / Intérêt d'un questionnaire de dépistage du risque de transmission de la maladie de Creutzfeldt-Jacob en consultation d'Ophtalmologie.

INTRODUCTION: The risk of prion transmission during an ophthalmic examination concerns all ophthalmologists screening patients at risk, a procedure normally based on collecting past history and clinical data. PATIENTS AND METHODS: The authors proposed a shortened version of a questionnaire where the patient provides only the past history by answering three questions, which are then validated by the ophthalmologist. RESULTS: This procedure was proposed to 500 patients. Only five patients answered one of the questions positively, and the ophthalmologist did not use any contact device during their examination. Of these five patients, none was confirmed to be at risk for prion transmission. CONCLUSION: This questionnaire seems to be a suitable way to compensate the lack of time and reduced staff in ophthalmology, whatever the ophthalmic practice may be.

[Trefoil factor family gene and peptide expression in pterygium]. / Etude des peptides en trèfle dans le ptérygion.

PURPOSE: Trefoil factor family (TFF) peptides (formerly P-domain peptides; trefoil factor) are small (7-12 kDa) protease-resistant secreted peptides designated pS2 (or TFF1), SP (TFF2) and ITF (TFF3). Human conjunctival goblet cells (GCs) are known to synthesize TFF, but TFF expression by these cells has not been studied in pathological conditions. We quantified trefoil factor family (TFF) gene transcripts in pterygium, and we immunolocalized TFF protein. METHODS: Eleven pterygium specimens were studied, together with 19 biopsy specimens of normal human conjunctiva as controls. TFF1 (pS2), TFF2 (spasmolytic peptide) and TFF3 (intestinal trefoil factor) mRNA expression was semiquantified by means of reverse-transcription polymerase chain reaction amplification (RT-PCR). TFF1, TFF2 and TFF3 mRNA levels were determined individually, relative to beta2 microglobulin housekeeping gene mRNA (internal standard), by coamplification of the target fragments and beta2 microglobulin in the same tube. Five pterygia and five normal human conjunctival biopsy specimens were also analyzed for TFF1 and mucin (MUC5AC) protein expression by immunostaining with monoclonal antibodies. Anti-PS2 (Zymed Laboratories, San Francisco), a mouse monoclonal antibody (MAb) against the 30 C-terminal amino acids of human TFF1, and P2802 (provided by Doctor Marie-Christine Rio, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM, Strasbourg, France), a mouse MAb directed against a synthetic peptide corresponding to the last 28 amino acids of TFF1, were used at 1/20 dilution. A mouse monoclonal antibody directed against the peptidic core of gastric M1 mucin was used as previously described. M1 immunoreactivity is encoded by the MUC5AC gene. RESULTS: TFF1 and TFF3 mRNA was expressed in all normal conjunctival and pterygium specimens. TFF2 mRNA was not expressed by either sample type, but was expressed by the positive control (human stomach cDNA). TFF1 mRNA expression was stronger in pterygium than in controls (p=0.02). TFF3 mRNA expression was similar in the two sample types (p=0.89). TFF are coexpressed and act in concert with mucins to protect mucous epithelia and trigger wound-healing responses. Inflammation and ulceration of the gastrointestinal tract are associated with increased TFF expression. Conjunctival GCs secrete TFF in both pigs and humans. We found that TFF1 mRNA was overexpressed in pterygium relative to healthy conjunctiva, whereas the TFF1 immunostaining patterns were similar. TFF1 protein expression was confined to goblet cells. However, whereas all GCs were positive for MUC5AC, not all GC were labeled by anti-TFF1 mAbs in either normal conjunctiva or pterygium. The observed TFF1 mRNA overexpression in pterygium was not associated with abnormal TFF1 peptide localization. Increased MUC5AC protein expression would be expected in pterygium, because of increased GC density. Indeed, in conjunctival diseases such as dry-eye syndrome in which GC density is decreased, mucin secretion is also decreased. This could explain the increased expression of TFF1 mRNA in pterygium, although not all GCs expressed TFF1 protein. TFF proteins are copackaged within mucous cell granules; TFF1 preferentially colocalizes with MUC5AC, and TFF3 with MUC2. However, we found some cell granules containing MUC5AC but not TFF1. The proportion of TFF1-negative GCs was similar in pterygium and normal conjunctiva. The normal TFF3 mRNA expression in pterygium was unexpected and suggests that only GCs involved in TFF1 secretion are overrepresented in this pathological tissue. TFF2 mRNA was undetectable in both normal conjunctiva and pterygium, possibly because of its copackaging in mucous cell granules and its preferential cosecretion with MUC6, which is not expressed in the conjunctiva. CONCLUSION: As in normal conjunctiva, the TFF1 and TFF3 genes are expressed by conjunctival goblet cells in pterygium, contrary to the TFF2 gene. Only TFF1 gene expression was elevated in pterygium compared to normal conjunctiva.

Gunshot wounds to the ureter: a 40-year experience at Grady Memorial Hospital.

PURPOSE: Because of the morbidity associated with missed ureteral injuries, a high index of suspicion must be present to diagnose this type of injury. We reviewed our 40 years of trauma experience at Grady Memorial Hospital. MATERIALS AND METHODS: We retrospectively reviewed the records of 118 patients with ureteral injuries secondary to a gunshot wound to the ureter from 1960 to 1999. All cases were reviewed for the mechanism of injury, location, initial urinalysis, imaging modalities, associated injuries, operative procedures and complications. RESULTS: Our population consisted of patients 14 to 71 years old, of whom 66 had right ureteral, 51 had left ureteral and 1 had bilateral injury. Urinalysis revealed no evidence of blood in the urine in 15% of the patients in whom the test was performed. Excretory urography had a false-negative rate of 33%. The injury was located at the proximal, mid and distal ureter in 43, 38 and 37 cases, respectively. Multiple surgical approaches were used depending on the location and severity of the defect. Only 1 patient had an isolated ureteral injury, while the remainder had associated injuries. Complications were present in 24 cases. CONCLUSIONS: To our knowledge this series of ureteral injuries is the largest reported to date. Because preoperative urinalysis and imaging studies are unreliable for ruling out injury, a high index of suspicion must be present. Furthermore, a predefined trauma protocol, as defined in our algorithm, decreases the number of missed ureteral injuries that may potentially complicate the outcome of an already critical case.

Distribution of cardiovascular disease risk factors by socioeconomic status among Canadian adults.

BACKGROUND: This study was designed to describe the distribution of risk factors for cardiovascular disease by socioeconomic status in adult men and women across Canada using the Canadian Heart Health Surveys Database. METHODS: The data were derived from provincial cross-sectional surveys done between 1986 and 1992. Data were obtained through a home interview and a clinic visit using a probability sample of 29,855 men and women aged 18-74 years of whom 23,129 (77%) agreed to participate. The following risk factors for cardiovascular disease were considered: elevated total plasma cholesterol (greater than 5.2 mmol/L), regular current cigarette smoking (one or more daily), elevated diastolic or systolic blood pressure (140/90 mm Hg), overweight (body mass index and lack of leisure-time physical activity [less than once a week in the last month]). Education and income adequacy were used as measures of socioeconomic status and mother tongue as a measure of cultural affiliation. RESULTS: For most of the risk factors examined, the prevalence of the risk factors was inversely related to socioeconomic status, but the relationship was stronger and more consistent for education than for income. The inverse relationship between socioeconomic status and the prevalence of the risk factors was particularly strong for smoking and overweight, where a gradient was observed: 46% (standard error [SE] 1.4) of men and 42% (SE 4.3) of women who had not completed secondary school were regular smokers, but only 12% (SE 1.0) of men and 13% (SE 0.9) of women with a university degree were regular smokers. Thirty-nine percent (SE 1.4) of men and 19% (SE 3.8) of women who had not completed secondary school were overweight, compared with 26% (SE 2.6) of male and 19% of female university graduates. The prevalence of leisure-time physical inactivity and elevated cholesterol was highest in both men and women in the lowest socioeconomic category, particularly by level of education. INTERPRETATION: The differences in the prevalence of risk factors for cardiovascular disease between socioeconomic groups are still important in Canada and should be considered in planning programs to reduce the morbidity and mortality from cardiovascular disease.

Gas chromatographic-mass spectrometric analysis of acids and phenols in distilled alcohol beverages. Application of anion-exchange disk extraction combined with in-vial elution and silylation.

A GC-MS protocol for profiling spirits, based on 19 acids and phenolic compounds, has been proposed and evaluated. The method combined a simple preconcentration procedure based on solid-phase (anion-exchange) disk extraction, and in-vial elution and silylation of the analytes. The derivatized extract was directly injected into the GC-MS system. These analytes were: C6, C8, C10, C12 acids, pyruvic acid, 2-furoic acid, succinic acid, fumaric acid, glutaric acid, lactic acid, glycolic acid, malic acid, tartaric acid, citric acid, vanillin, syringaldehyde, coniferaldehyde, vanillic acid and gallic acid. The profiles of six different spirits were found reproducible from day-to-day with <20% RSD for measurements of most of the analytes at different concentrations. Recoveries of individual analytes appear to be affected by the level of tannins in the spirits, and they varied from sample to sample. The method of standard addition was used to quantify age-related analytes. Good linearity of response with correlation coefficients in the range of 0.992-0.999 was obtained. The results of the study indicate that for spirits of the same brand but of different ages, the amounts of these analytes appear to increase with the ageing period.

Minilaparotomy radical retropubic prostatectomy: updated technique and results.

The purpose of this article is to reduce the incisional morbidity associated with standard radical retropubic prostatectomy using the minilaparotomy incision developed for pelvic lymph-node dissection, which was applied to radical retropubic prostatectomy. More than 522 patients underwent minilaparotomy radical retropubic prostatectomy from 1991 to 1997. Preoperative evaluation included history, physical examination, prostate-specific antigen (PSA), and Gleason's grade. Postoperative follow-up included serial PSA measurements and a determination of continence. The surgical technique is described in detail. Two hundred sixty-five patients responded to the mailed questionnaire out of a total 522 patients. Satisfactory continence, defined as 0 to 1 pad per day, was achieved in 85% of patients, and 83% of patients had a PSA < 0.2 at an average follow-up of 2.6 years. There was no operative mortality, and overall complication rate was similar to other surgeons. The typical patient was discharged home 3 days postoperatively. Minilaparotomy radical retropubic prostatectomy compares favorably with standard radical retropubic prostatectomy.

Brachial, radial, or femoral approach for elective Palmaz-Schatz stent implantation: a randomized comparison.

UNLABELLED: From October 1994 to November 1995, 150 male eligible patients were randomly assigned to Palmaz-Schatz stent implantation through 6 French catheters using the femoral (puncture) (n = 56), radial (puncture) (n = 56), or brachial (cutdown) (n = 38) approach at 6 participating Belgian centers. Acenocoumarol was given for 1 month after stenting. END POINTS: Primary-entry site complications (bleeding, haematoma, transfusion, occlusion, surgery) poststent implantation. Secondary-success rate, stent thrombosis, Q or non Q wave MI, repeat PTCA, CABG, CVA, haemorrage, death. There were no statistically significant differences between the three groups for base line and angiographic patient characteristics, procedural characteristics, in hospital outcome, average hospitalisation time after stenting, events during the month after stenting, or local complications at 1 month follow-up. The only statistically significant difference was the arterial time of the procedure: mean +/- SD (minutes) brachial 31.0 +/- 10.02 *P < 0.001, femoral 42.2 +/- 21.8, radial 55.8 +/- 31.3 **P < 0.0001 (*brachial vs. femoral, **brachial vs. radial). There was a clear trend toward more technical difficulties and more problems with the radial approach. In each group: vascular surgery at entry site: 0%, blood transfusion: 0%. In our study, local complications and length of hospital stay were similar with the three possible approaches, and brachial approach was associated with a shorter arterial time.

Incidence of granulomatous prostatitis and acid-fast bacilli after intravesical BCG therapy.

OBJECTIVES: To determine the incidence of granulomatous prostatitis and acid-fast bacilli (AFB) after intravesical bacillus Calmette-Guerin (BCG) therapy for superficial bladder transitional cell carcinoma (TCC) or carcinoma in situ (CIS). METHODS: One hundred nineteen men underwent radical cystoprostatectomy for invasive bladder cancer from January 1, 1980 through December 31, 1995. Twelve patients had received intravesical BCG therapy before undergoing cystoprostatectomy. Nine men who did not receive intravesical BCG therapy before undergoing cystoprostatectomy served as controls. The surgical specimens were examined with a Ziehl-Neelsen stain for the presence of granulomatous prostatitis and for the presence of AFB. RESULTS: Granulomatous prostatitis was identified in 9 of 12 patients (75%) who had received intravesical BCG therapy. AFB were identified in 7 of 9 patients (77%) with granulomatous prostatitis. CONCLUSIONS: Pathologic evidence of granulomatous prostatitis with AFB is a common occurrence after intravesical BCG therapy and its incidence is far greater than the reported incidence of symptomatic granulomatous prostatitis. AFB discovered during the evaluation of either an increased level of prostate-specific antigen or prostate nodule in otherwise asymptomatic men may require no specific therapy.

Assay, Purification, and Partial Characterization of Choline Monooxygenase from Spinach.

The osmoprotectant glycine betaine is synthesized via the path-way choline -> betaine aldehyde -> glycine betaine. In spinach (Spinacia oleracea), the first step is catalyzed by choline monooxygenase (CMO), and the second is catalyzed by betaine aldehyde dehydrogenase. Because betaine aldehyde is unstable and not easily detected, we developed a coupled radiometric assay for CMO. [14C]Choline is used as substrate; NAD+ and betaine aldehyde dehydrogenase prepared from Escherichia coli are added to oxidize [14C]betaine aldehyde to [14C]glycine betaine, which is isolated by ion exchange. The assay was used in the purification of CMO from leaves of salinized spinach. The 10-step procedure included polyethylene glycol precipitation, polyethyleneimine precipitation, hydrophobic interaction, anion exchange on choline-Sepharose, dimethyldiethanolamine-Sepharose, and Mono Q, hydroxyapatite, gel filtration, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Following gel filtration, overall purification was about 600-fold and recovery of activity was 0.5%. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a polypeptide with a molecular mass of 45 kD. Taken with the value of 98 kD estimated for native CMO (R. Brouquisse, P. Weigel, D. Rhodes, C.F. Yocum, A.D. Hanson [1989] Plant Physiol 90: 322-329), this indicates that CMO is a homodimer. CMO preparations were red-brown, showed absorption maxima at 329 and 459 nm, and lost color upon dithionite addition, suggesting that CMO is an iron-sulfur protein.

Differential accumulation of hydroxyproline-rich glycoproteins in bean root nodule cells infected with a wild-type strain or a C4-dicarboxylic acid mutant of Rhizobium leguminosarum bv. phaseoli.

An antiserum raised against deglycosylated hydroxyproline-rich glycoproteins (HPGPs) from melon (Cucumis melo L.) was used to study the relationship between Rhizobium infection and induction of HRGPs in bean (Phaseolus vulgaris L.) root nodule cells infected with either the wild-type or a C4-dicarboxylic acid mutant strain of Rhizobium leguminosarum bv. phaseoli. In effective nodules, where fixation of atmospheric dinitrogen is taking place, HRGPs were found to accumulate mainly in the walls of infected cells and in peribacteroid membranes surrounding groups of bacteroids. Internal ramifications of the peribacteroid membrane were also enriched in HRGPs whereas the peribacteroid space as well as the bacteroids themselves were free of these glycoproteins. In mutant-induced root nodules, HRGPs were specifically associated with the electron-dense, laminated structures formed in plastids as a reaction to infection by this mutant. The presence of HRGPs was also detected in the host cytoplasm. The aberrant distribution of HRGPs in infected cells of mutant-induced nodules likely reflects one aspect of the altered host metabolism in relation to peribacteroid-membrane breakdown. The possibility that the antiserum used for HRGP localization may have cross-reacted with ENOD 2 gene products is discussed in relation to amino-acid sequences and sites of accumulation.

The occurrence of unusual laminated structures rich in ß-1,4-glucans in plastids of Phaseolus vulgaris root-nodule cells infected by an ineffective C4-dicarboxylic-acid mutant of Rhizobium leguminosarum bv. phaseoli.

Root nodules induced in Phaseolus vulgaris L. by the wild-type (WT) and a C4-dicarboxylic-acid mutant strain of Rhizobium leguminosarum biovar. phaseoli were compared on the basis of ultrastructure and cytochemistry of cellulose subunits. The mutant bacteroids failed to colonize infected host cells in a normal manner, and presented a premature degenerative appearance. Starch granules, rough endoplasmic reticulum and mitochondria were found to accumulate in the ineffective nodules. The most striking difference between effective and ineffective nodules was the presence of unusual spherical, laminated structures in plastids of mutant-infected host cells only. Cytochemical observations showed that these structures contain ß-1,4-glucans. The presence of ß-1,4-glucans within such structures may be caused by the activity of a cellulase which is produced by either the bacteroids or the host cell and is locally hydrolyzing the host cell-wall, thus releasing cellulose subunits into the cytoplasm. Another possibility is denovo synthesis of ß-1,4-glucans in the host cell.