Local anaesthetic transperineal (LATP) prostate biopsy using a probe-mounted transperineal access system: a multicentre prospective outcome analysis

OBJECTIVES

To assess the feasibility of local anaesthetic transperineal (LATP) technique using a single-freehand transperineal (TP) access device, and report initial prostate cancer (PCa) detection, infection rates, and tolerability.

PATIENTS AND METHODS

Observational study of a multicentre prospective cohort, including all consecutive cases. LATP was performed in three settings: (i) first biopsy in suspected PCa, (ii) confirmatory biopsies for active surveillance, and (iii) repeat biopsy in suspected PCa. All patients received pre-procedure antibiotics according to local hospital guidelines. Local anaesthesia was achieved by perineal skin infiltration and periprostatic nerve block without sedation. Ginsburg protocol principles were followed for systematic biopsies including cognitive magnetic resonance imaging-targeted biopsies when needed using the PrecisionPoint™ TP access device. Procedure-related complications and oncological outcomes were prospectively and consecutively collected. A validated questionnaire was used in a subset of centres to collect data on patient-reported outcome measures (PROMs).

RESULTS

Some 1218 patients underwent LATP biopsies at 10 centres: 55%, 24%, and 21% for each of the three settings, respectively. Any grade PCa was diagnosed in 816 patients (67%), of which 634 (52% of total) had clinically significant disease. Two cases of sepsis were documented (0.16%) and urinary retention was observed in 19 patients (1.6%). PROMs were distributed to 419 patients, with a 56% response rate (n = 234). In these men, pain during the biopsy was described as either 'not at all' or 'a little' painful by 64% of patients. Haematuria was the most common reported symptom (77%). When exploring attitude to re-biopsy, 48% said it would be 'not a problem' and in contrast 8.1% would consider it a 'major problem'. Most of the patients (81%) described the biopsy as a 'minor or moderate procedure tolerable under local anaesthesia', while 5.6% perceived it as a 'major procedure that requires general anaesthesia'.

CONCLUSION

Our data suggest that LATP biopsy using a TP access system mounted to the ultrasound probe achieves excellent PCa detection, with a very low sepsis rate, and is safe and well tolerated. We believe a randomised controlled trial comparing LATP with transrectal ultrasound-guided biopsy (TRUS) to investigate the relative trade-offs between each biopsy technique would be helpful.

Sex-related differences in the thanatomicrobiome in postmortem heart samples using bacterial gene regions V1-2 and V4

Recent studies have revealed distinct thanatomicrobiome (microbiome of death) signatures in human body sites after death. Thanatomicrobiome studies suggest that microbial succession after death may have the potential to reveal important postmortem biomarkers for the identification of time of death. We surveyed the postmortem microbiomes of cardiac tissues from 10 corpses with varying times of death (6-58 h) using amplicon-based sequencing of the 16S rRNA gene' V1-2 and V4 hypervariable regions. The results demonstrated that amplicons had statistically significant (P < 0·05) sex-dependent changes. Clostridium sp., Pseudomonas sp., Pantoea sp. and Streptococcus sp. had the highest enrichment for both V1-2 and V4 regions. Interestingly, the results also show that V4 amplicons had higher abundance of Clostridium sp. and Pseudomonas sp. in female hearts compared to males. In addition, Streptococcus sp. was solely found in male heart samples. The distinction between sexes was further supported by principle coordinate analysis, which revealed microbes in female hearts formed a distinctive cluster separate from male cadavers for both hypervariable regions. This study provides data that demonstrates that two hypervariable regions show discriminatory power for sex differences in postmortem heart samples.

SIGNIFICANCE AND IMPACT OF THE STUDY

The findings represent preliminary data of the first thanatomicrobiome investigation of a comparison between 16S rRNA gene V1-2 and V4 amplicon signatures in corpse heart tissues. The results demonstrated that V4 hypervariable region amplicons had statistically significant (P < 0·05) sex-dependent microbial diversity. For example, Streptococcus sp. was solely found in male postmortem heart tissues. Interestingly, the results also show that V4 amplicons had higher abundance of Clostridium sp. and Pseudomonas sp. in female heart tissues compared to males. The finding of Clostridium sp. supports the postmortem clostridium effect in corpse heart tissues.

Growth of Octopine-Catabolizing Pseudomonas spp. under Octopine Limitation in Chemostats and Their Potential To Compete with Agrobacterium tumefaciens

The growth characteristics of five octopine-catabolizing pseudomonads have been determined in batch and continuous cultures. All five strains belonged to rRNA homology group I and showed a more psychrotrophic growth pattern than did Agrobacterium tumefaciens B6 and ATCC 15955. In chemostats limited by octopine, either as the source of carbon and nitrogen or the sole source of nitrogen, maximum specific growth rates and substrate affinities were lower than those in chemostats limited by glutamate. These growth dynamics were similar to those observed for Agrobacterium strains B6 and ATCC 15955 even though the catabolic genes and pathways are believed to be different in the two genera. An analysis of the yields in octopine-limited chemostats indicated that the use of octopine as the sole source of carbon and nitrogen was grossly inefficient. Octopine and presumably lysopine and octopinic acid provided a better source of nitrogen than of carbon. One of the Pseudomonas fluorescens strains, E175D, was able to produce its highest yield on octopine as a nitrogen source. Competition models formulated on pure culture parameters indicated that two of the Pseudomonas spp. would dominate A. tumefaciens B6 and ATCC 15955 when in simple competition for octopine as a limiting substrate.

Competition of Octopine-Catabolizing Pseudomonas spp. and Octopine-Type Agrobacterium tumefaciens for Octopine in Chemostats

The ability of two octopine-catabolizing Pseudomonas spp. and two virulent octopine-type Agrobacterium tumefaciens to compete for substrates has been examined in chemostats. In dual cultures with octopine or glutamate as the limiting carbon or nitrogen source, Pseudomonas fluorescens B99A and E175D always dominated over A. tumefaciens B6 or ATCC 15955. The growth dynamics of each strain in pure culture indicated that some form of antagonism was occurring in dual culture to permit the predominance of the pseudomonads under certain conditions. Although both pseudomonads fluoresce, pyoverdine was not responsible for the observed inhibition. An unidentified antibiotic secreted by both pseudomonads is believed to be responsible. A. tumefaciens B6 grew synergistically in the presence of P. fluorescens B99A with octopine as the limiting nitrogen source. This behavior of Agrobacterium strain B6 may help overcome its grossly inefficient use of octopine as previously reported. The ability of these two pseudomonads to outcompete the agrobacteria under all conditions tested raises the possibility that under field conditions, infectious agrobacteria may be succeeded by opine-catabolizing pseudomonads around crown gall tumors and in the rhizosphere.

A prospective evaluation of the management of acute pyelonephritis in adults referred to urologists

In order to assess whether it is appropriate and clinically efficient to admit adults with 'clinically diagnosed' acute pyelonephritis (APN) under urologists, as is current practice in many NHS hospitals, a prospective study was undertaken over nine months in an NHS teaching hospital. Thirty-nine patients with clinical APN were admitted to the urology unit; all were pyrexial and 30 (77%) had typical features of rigor, flank pain and irritative lower urinary tract symptoms. Twenty-one (54%) had positive urine cultures, 31 (79%) had parenteral antibiotics, while another three (7%) had oral agents initially. The remaining five (14%) were continued on agents initiated by their GPs before admission. Thirty-three (85%) had imaging procedures with eight significant anomalies being noted. Urgent invasive intervention was required in only four (10%) patients; length of stay varied from one to 25 days. Uncomplicated moderate to severe APN in adults may be treated safely without the need for admission to the urology unit, either in the outpatient setting or on an acute admissions observation ward. Complicated cases requiring intervention can be transferred to the urologist once recommended investigations have been undertaken. This care pathway may help to reduce cancellations of elective urological cases and is likely to be more cost-effective for the NHS by reducing unnecessary admissions.

Fibrinogen, lipoprotein (a) and lipids in patients with erectile dysfunction. A preliminary study

BACKGROUND

Erectile dysfunction is associated with cardiovascular risk factors (e.g. hypertension, smoking, dyslipidemia and diabetes) and is more common in patients with cardiovascular disease. We therefore assessed the prevalence of two predictors of vascular events, fibrinogen and lipoprotein-a, in patients with and without erectile dysfunction.

METHODS

Men with erectile dysfunction (48 non-smokers, 48 smokers), aged 45-70 years, were compared with controls (21 non-smokers, 21 smokers) with normal erectile function and no known pathology.

RESULTS

Serum total cholesterol was significantly higher in non-smokers with erectile dysfunction compared to both control non-smokers and erectile dysfunction smokers. Men with erectile dysfunction who smoked had a significantly higher plasma fibrinogen level than control smokers. Similarly, men with erectile dysfunction, who did not smoke had higher levels of plasma fibrinogen compared to both smokers and non-smokers without erectile dysfunction. No significant difference in serum lipoprotein-a values was found.

CONCLUSIONS

These findings support the concept that cardiovascular risk factors are predictors of erectile dysfunction and that this may be another manifestation of vascular disease.

A 7-year audit in a single centre of the results of the modified template retroperitoneal lymph node dissection for testicular teratoma

OBJECTIVE

To audit the results of retroperitoneal lymph node dissection (RPLND) after chemotherapy for testicular nonseminomatous germ cell tumour (NSGCT) in a single centre over a 7-year period, using a modified template technique via a midline transabdominal approach.

PATIENTS AND METHODS

Outcome data were collected prospectively on all patients undergoing RPLND for a residual retroperitoneal mass after chemotherapy for NSGCT between October 1990 and March 1998; 28 patients underwent 32 RPLNDs over this period.

RESULTS

The clinical stage at presentation was stage I in three patients (12%), stage II in 15 (54%), stage III in one (4%) and stage IV in nine (32%). The histological classification included malignant teratoma differentiated in one patient, malignant teratoma intermediate in 12 (43%) and malignant teratoma undifferentiated in 12. Tumour markers were positive immediately before surgery in four patients. A midline transabdominal approach was used in 31 of the procedures. The size of the retroperitoneal tumour mass was <3 cm in four patients (13%), 4-8 cm in 16 (50%) and >9 cm in 12 (38%). Histology of the mass showed residual differentiated teratoma in 17 (53%), undifferentiated teratoma in six (19%), necrosis only in six (19%), adenocarcinoma in one and angiosarcomatous differentiation in two. There was no perioperative mortality. Eight patients had permanent loss of ejaculation (29%) and two had erectile dysfunction (7%). Five patients (20%) subsequently developed recurrent disease; three (12%) underwent reoperation for disease relapse (one requiring two further procedures), whilst two (8%) died from recurrent disease.

CONCLUSION

An abdominal approach via a midline incision provides satisfactory access with minimal morbidity in most patients. Results comparable with larger series can be achieved in regional centres.

Thrombotic risk factors associated with transurethral prostatectomy

OBJECTIVE

To ascertain the potential thrombotic risk associated with transurethral prostatectomy (TURP).

PATIENTS AND METHODS

The changes in coagulation variables were assessed in a prospective study of 40 patients undergoing TURP.

RESULTS

There was a significant increase in thrombin-antithrombin complexes 6 h after TURP (anova, P=0.01) combined with a significant decrease in activated partial thromboplastin time (anova, P=0.006), suggesting a postoperative hypercoagulable state. The significant increase in d-dimer 24 h after TURP (anova, P=0.015) in the absence of any significant rise in tissue plasminogen activator antigen levels perioperatively (anova, P=0.737) suggests a physiological fibrinolytic response to the developing procoagulant state. The absence of any significant increase in plasminogen activator inhibitor-1 antigen perioperatively (anova, P=0.348) suggests the observed hypercoagulability is not due to a 'fibrinolytic shutdown' reported in other forms of surgery.

CONCLUSION

TURP is associated with a hypercoagulable prothrombotic state; aspirin withdrawal perioperatively may be hazardous, and low-dose heparin prophylaxis for venous thrombosis should be considered.

Contemporary results of radical radiotherapy for bladder transitional cell carcinoma in a district general hospital with cancer-centre status

OBJECTIVE

To assess the current efficacy and safety of definitive external beam radiotherapy (EBRT) in the treatment of invasive bladder transitional cell carcinoma (TCC) in a district general hospital with cancer-centre status.

PATIENTS AND METHODS

The case notes of all patients with bladder TCC undergoing EBRT with curative intent over an 8-year period (1988-95) were reviewed. Additional missing outcome data were collected.

RESULTS

In all, 120 patients (109 men; median age 70 years, range 34-90) underwent radical EBRT (40-65 Gy; fraction median=20) over the 8-year period. Staging, as assessed by examination under anaesthesia and computed tomography, was T1 in 16%, T2 in 43%, T3 in 38% and T4 in 3%. In 96 patients (80%) the tumour was poorly differentiated (G3). The overall morbidity at 12 months was 12%; proctitis occurred in nine patients (8%) and cystitis in five (4%). Sixty-seven patients (59%) developed a local recurrence and in 36 (30%) this was invasive. The overall median survival was 60 months. Thirty-three patients underwent salvage cystectomy with a subsequent median survival of 12.5 months.

CONCLUSION

Modern radical multifraction EBRT in invasive bladder TCC has a low morbidity, with an overall median survival of 5 years.

Thrombelastographic evaluation of coagulation in transurethral prostatectomy

OBJECTIVE

To assess the changes in overall coagulation status and define the degree of systemic fibrinolysis occurring in patients undergoing transurethral prostatectomy (TURP).

PATIENTS AND METHODS

Thirty patients undergoing TURP, 23 for benign prostatic hyperplasia and seven for prostatic carcinoma, were studied prospectively. Serial venous blood samples were taken using the two-syringe technique. Samples were taken before, during and at intervals up to 72 h and 10-14 days after surgery. Thrombelastography (TEG) was performed on native whole blood samples. Peri-operative blood loss was assessed, until the catheter was removed, by photometric estimation of the haemoglobin content of the irrigant fluid and the measurement of clot volume.

RESULTS

There was no evidence of fibrinolysis (TEG Percentage Clot Lysis Ly60 > 15%) in any patient over the whole peri-operative period. There was a significant change in the mean TEG variables towards hypercoagulation from 3 h until 10-14 days postoperatively, compared with the pre-operative values (P < 0.05). There was a significant correlation between blood loss and clot volume.

CONCLUSION

These results question the role of systemic fibrinolysis in primary and secondary haemorrhage following TURP and thus the rationale of using antifibrinolytics in these patients. The persistent hypercoagulable state post-operatively indicates a possible role of hypercoagulability in clot retention.

Autoradiographic localization of nitric oxide synthase binding sites in normal and diabetic rat corpus cavernosum

OBJECTIVES

To investigate density and distribution of nitric oxide synthase (NOS) binding sites in rat cavernosal tissue, and to assess any changes brought about by the onset of diabetes mellitus.

METHODS

Hyperglycaemic non-ketonuric diabetes mellitus was induced in 5 rats using streptozotocin. The penises were excised from these rats 2 months after the administration of streptozotocin and stored at -70 degrees C. Longitudinal serial sections (6 microns) were cut in a cryostat and thaw mounted onto gelantinized microscope slides. Low- and high-resolution autoradiography was performed using a radioligand for NOS. Densitometric analysis was performed on the autoradiographs and the results compared with those obtained from 5 age-matched no-diabetic rats.

RESULTS

NOS binding was primarily localized to the endothelium lining the cavernosal lacunar spaces. Significantly increased binding of NOS was seen in the diabetic cavernosal tissue 2 months after induction of diabetes mellitus.

CONCLUSIONS

NOS binding is present on the endothelium of the rat corpus cavernosum and is increased in diabetic rats 2 months after streptozotocin administration. This increase in NOS binding may be part of the endothelial dysfunction which is reported in the corpus cavernosum of diabetic patients or rats.

The density and distribution of endothelin 1 and endothelin receptor subtypes in normal and diabetic rat corpus cavernosum

OBJECTIVE

To investigate the density and distribution of endothelin 1(ET-1) and endothelin receptor subtypes in rat cavernosal tissue, and to assess any changes brought about by the onset of diabetes mellitus (DM).

MATERIALS AND METHODS

Hyperglycaemic non-ketotic diabetes mellitus was induced in five rats using streptozotocin (STZ). Two months later the penises were excised and stored at -70 degrees C. Longitudinal serial sections (6 microns) were cut using a cryostat and thaw- mounted onto gelatinized microscope slides. Low and high resolution autoradiographs were taken using radioligands for ET-1 and endothelin A (ETA) and endothelin B (ETB) receptors and the autoradiographs analysed densitometrically. These results were compared with those from five age-matched control rats.

RESULTS

ET-1 and ETA receptor binding was primarily localized to the endothelium lining the cavernosal lacunar spaces: trabecular corporeal smooth muscle was much less intensely stained. No ETB receptor binding could be demonstrated, but increased binding of ET-1 and ETA receptors was seen in the diabetic cavernosal tissue.

CONCLUSION

ET-1 and ETA receptor binding is increased in diabetic rat cavernosal tissue. A reduction in receptor linked nitric oxide (NO) release has previously been reported in diabetic rats. This finding may provide an explanation for the upregulation of ET-1 and ETA receptor binding in the diabetic rat.

A full factorial analysis of nine factors influencing in vitro antagonistic screens for potential biocontrol agents

The effect of nine factors on the outcome of classic in vitro screens testing the antagonistic action of endophytic bacterial isolates from grape vines against virulent Agrobacterium vitis has been examined. These factors were (i) the strain of A. vitis, (ii) the strain of endophyte, (iii) the growth medium of the pathogen, (iv) the growth medium of the endophyte, (v) the temperature of growth of the pathogen, (vi) the temperature of growth of the endophyte, (vii) the pH of growth of the pathogen, (viii) the pH of growth of the endophyte, and (ix) the medium of the assay plate. Analyses of variance of the full factorial design incorporating main effects and two- and three-way interactions accounted for 66% of the variance. All nine factors had a significant effect on the diameter of inhibition zones (p < 0.001). An examination of the three-way interactions revealed that generalizations were difficult to draw; each target agrobacterium had a specific response to a given antagonistic isolate. It was possible to determine that the growth history of bacterial strains, before they were administered to an assay plate to test for antagonism (especially the composition of the growth medium and the temperature of growth), had a profound effect on the outcome of the test. Generally the more chemically defined media produced less inhibition whereas the lower growth temperature of 15 degrees C produced more inhibition. These findings could be relevant to in situ inhibitory activity. The method used to conduct the inhibitory screen (order of strain application and the medium of the assay plate) had a profound influence on the results. These influences add to the caution necessary in the use of in vitro antagonistic screens for finding successful biocontrol agents.

Primary non-Hodgkin's lymphoma of the prostate gland: case report and review of the literature

A patient with primary extranodal non-Hodgkin's lymphoma arising in the prostate gland is presented. The central role of transrectal ultrasonography in the diagnosis and response to chemotherapy is discussed.

Commitment to service is good strategy

Hospital leaders need a clear vision of how corporate purpose and function are aligned with mission. The one concept that can unite all of these areas is service, say Chip R. Bell, Ph.D., and Ron Zemke, of Performance Research Associates Inc. With the proper service focus, a hospital can be both patient- and marketing-oriented.

Potential of Agrobacterium tumefaciens and Octopine-Utilizing Fluorescent Pseudomonas Strains To Attach to Susceptible Potato Tissues

The binding characteristics of two octopine-catabolizing pseudomonads, Pseudomonas fluorescens B99A and E175D, which were isolated from crown galls, have been examined. The binding of strain B99A to potato disks was very weak, followed a Freundlich isotherm, and was temperature and pH independent. Strain E175D displayed strong attachment and followed a Langmuir isotherm. Despite these fundamental differences in binding characteristics, when each strain was placed in competitive binding assays with either Agrobacterium tumefaciens B6 or A. tumefaciens ATCC 15955, the number of bound pseudomonad cells decreased compared with those obtained in independent trials. Furthermore, the binding of A. tumefaciens cells was increased. In prebinding experiments, in which the potato disks were bound with the pseudomonads before exposure to the agrobacteria, the number of bound pseudomonad cells again decreased. This implies that increased desorption was occurring. In these prebinding studies, the numbers of bound A. tumefaciens ATCC 15955 increased, but the number of bound A. tumefaciens B6 remained the same. The mechanism for this observed synergism on the binding of agrobacterial cells and the depression in bound pseudomonad cells is believed to be alterations in the electrostatic or ionic charges on the plant and bacterial cell surfaces. The synergistic effect on A. tumefaciens undermines the use of these pseudomonads as potential biocontrol agents for crown gall.

Growth of Agrobacterium tumefaciens under octopine limitation in chemostats

Agrobacterium tumefaciens B6 and ATCC 15955 were grown under octopine or glutamate limitation in chemostats. Examination of the maximum specific growth rate (mu max) and substrate affinity (KS) for each strain indicated that strain B6 was highly inefficient in its use of octopine as either a nitrogen or carbon source compared with strain ATCC 15955. Examination of the yield coefficients showed that in both strains octopine was used more efficiently as a nitrogen source than as a carbon source. The data permitted predictions to be made concerning the outcome of competition for a single limiting substrate. Under octopine limitation, strain ATCC 15955 should dominate; under glutamate limitation, strain B6 should dominate. The results of an observed competition with glutamate as the limiting substrate confirmed the latter prediction, although B6 did dominate at a rate faster than was predicted from simple competition theory. B6 displayed higher growth rates and substrate affinities than ATCC 15955 on all concentrations of glutamate. The yield of B6 on octopine was also considerably higher. This latter attribute could provide an ecological advantage to B6 because of the importance of yield in the fate of competitions under multisubstrate regimens. These will be the most prevalent regimens in the area around the tumor (tumorosphere) or the rhizosphere. The increased performance on glutamate could provide an advantage in an opine-free environment when B6 is growing as a saprophyte.

Facilitating the vocational-interpersonal skills of mentally retarded individuals

A program was designed to teach interpersonal skills to mentally retarded individuals in order to facilitate their vocational adjustment and prevent job termination. Thirty-five retarded young adults were randomly assigned to a skills-training, coaching, or no-treatment control group. The skills-training and coaching groups met for 12 sessions and 6 follow-up meetings. The skills-training group learned appropriate ways of responding to difficult work-related interpersonal situations. Modeling, coaching, and behavioral rehearsal were the treatment procedures. The coaching group discussed the same interpersonal situations; however, modeling and behavioral rehearsal were not employed. Results indicated that the skills-training group improved their interpersonal skills, social competence, vocational problem behavior, and length of employment. Some positive changes were noted for the coaching group. The results provide support for training interpersonal skills prior to community vocational placement.

Modifying impulsive responding in conduct-disordered institutionalized boys

24 institutionalized aggressive, impulsive males aged 10 to 16 participated in 14 sessions of training in the use of “rules” for the solution of cognitive tasks. When compared to 21 controls who completed the same tasks but were not exposed to the “rules,” the experimental group shifted toward less impulsive responding on the Porteus Maze Q score on posttest.

Seasonal fluctuations in river bacteria as measured by multivariate statistical analysis of continuous cultures

Forty-eight continuous culture enrichments were performed on summer and winter water samples from two contrasting rivers. The cell output from each chemostat was dependent on the temperature and nitrogen concentration of each enrichment. The diversity of the populations from the continuous cultures, as assessed by species diversity analysis, was always greater than populations obtained on agar plates. However, the species isolated exclusively by continuous culture in these experiments were not unique to the chemostat. All of these species had been isolated at some time on plates directly. High nitrogen concentrations were found to decrease diversity. Populations sampled during the winter were influenced primarily by the concentration of nitrogen. Summer isolates were affected mainly by the temperature of the culture medium. The nutritional versatility of the population was not affected by enrichment of the continuous culture.

Attached and Free-Floating Bacteria in a Diverse Selection of Water Bodies

The contribution of attached and free-floating bacteria to the bacterial numbers and heterotrophic uptake in 44 diverse aquatic environments was studied. A factor analysis reduced the variability of the raw data base to three major factors explaining 53.6% of total variance. These factors were (i) salinity, (ii) heterotrophic uptake, and (iii) particulate load. A cluster analysis categorized the 44 habitats into five distinct environmental types based on these three factors. There was no significant pattern in the distribution of attached versus free-floating bacteria when assessed by epifluorescent microscopy. However the contribution of attached bacteria to the uptake of an amino acids mix was reduced in marine waters. Heavy particulate loads resulted in an increased percentage uptake of amino acids and glucose from the attached bacteria. Uptake response was found to be substrate specific especially in oliogotrophic freshwater. Amino acid uptake was more associated with the attached fraction, whereas glucose uptake was mediated more by the free-floating fraction.

Correlations Between Predominant Heterotrophic Bacteria and Physicochemical Water Quality Parameters in Two Canadian Rivers

The heterotrophic bacterial populations in two contrasting rivers have been examined over a period of 1 year. The populations were analyzed (i) as total heterotrophic counts, (ii) as species numbers, using numerical taxonomy, (iii) by diversity indices, and (iv) by factor analysis. Isolates were obtained by plating directly from water samples and by chemostat enrichment. Four factors emerged which profiled the bacterial community and were common to both rivers. They were, in order of decreasing importance, fermentative metabolism, inorganic nitrogen metabolism, fluorescence-oxidative metabolism, and lack of starch hydrolysis. Several factors produced significant correlations with a range of physicochemical parameters, which were also measured. The correlations suggested an intricate algal-bacterial interaction. The oxidative metabolism factor correlated with rainfall in one river, suggesting that the oxidative bacteria may be washed in from the surrounding land. In the other river, the oxidative-fermentative factor correlated negatively with sunshine. Factor analysis was the most effective method for revealing correlations between bacterial characteristics and the environmental parameters; however, the use of a variety of methods provided more insight into the ecological aspects.

Assessing the problematic interpersonal skills of mentally retarded individuals in a vocational setting

The present paper reports on two studies which were designed to assess specific interpersonal situations and behaviors which interfere with a mentally retarded individual's adjustment to a vocational setting. In the first study, lists of problematic interpersonal situations and problematic behaviors were generated based on (a) interviews with prevocational teachers, school personnel, and work supervisors in a sheltered workshop setting, and (b) behavioral observations of workers in prevocational classes and a workshop setting. The list of problematic behaviors was further evaluated by work supervisors to determine the frequency and seriousness of each behavior. This information provided a basis for establishing training priorities in an interpersonal skills training program for mentally retarded individuals. In a second study, problem behavior ratings were obtained from prevocational teachers and residential supervisors for 40 mentally retarded individuals. Teachers additionally rated each individual using several standardized assessment scales (Behavior Problem Checklist, AAMD Adaptive Behavior Scale, Vocational Competency Scale). After placement in a sheltered workshop setting, problem behavior ratings were obtained from work supervisors for each individual, and the length of successful employment was assessed. Intercorrelations among measures and across raters provided initial support for the validity and reliability of the problem behavior list. Implications for future researching and training on interpersonal-vocational skills are discussed.

Time and temperature a reply to Green and Simpson

The arguments are examined that reanalysis of the data in Bell (1975) leads to a rejection of his conclusions. The author maintains that the specific hypothesis that a metabolic pacemaker controls time estimation is not supported by his data.

Effects of lowered temperature on time estimation

Body (ear) temperature of 14 subjects was lowered in order to examine its effect upon performance of a task requiring estimation of an interval of 60 s. Although there was some evidence that subjects counted more slowly at lower body temperatures, the inconsistency of the effect was such as to cast doubt on the hypothesis of a “biochemical clock” or “metabolic pacemaker” in the brain said to subserve human time estimation of brief intervals.

Accurate performance of a time-estimation task in relation to sex, age, and personality variables

The accuracy with which a rate of digit count was estimated as 1 digit/sec. was assessed in relation to the sex, age, and selected personality characteristics of Ss Marginally significant relationships between time-estimation accuracy data and age were found for each sex. Women tended to be slightly less accurate and more variable in their estimations than men. Few scores derived from the 16 PF Questionnaire were associated with time-estimation accuracy. The findings serve to confirm the inconsistencies existing in the time-estimation literature and point to the necessity of further research examining the interaction of variables before a theory relating personality characteristics to time-estimation performance may be attempted.

Thermal limits for industrial workers

Bell, C. R., and Watts, A. J. (1971).Brit. J. industr. Med.,28, 259-264. Thermal limits for industrial workers. The literature on relationships between man's comfort, efficiency, and physical well-being and the nature of his thermal working environment is diverse and highly specific. Industrial practice requires more general `concensus' data on which to base reasonable recommendations for the establishment of thermal environmental limits. A series of three such limits is proposed which provide protection of the workers' comfort, efficiency, and physiological safety.

For sedentary workers it is suggested that in summer an upper limit of 21·8°C C.E.T. is advisable if not less than 80% of workers are to be free from discomfort. Against a similar criterion in winter a lower limit of 15·5°C C.E.T. is proposed. An extrapolation of data from laboratory to industrial work-places provides a suggested limit for efficiency at skilled tasks at 26·7°C C.E.T. Finally, a limit of environmental severity based upon an absence of severe physiological distress in 95% of exposed workers is proposed which varies with the age and physical fitness of the workers and the physical demands of the work they are called upon to perform.