Age-related changes and longitudinal stability of individual differences in ABCD Neurocognition measures

Temporal stability of individual differences is an important prerequisite for accurate tracking of prospective relationships between neurocognition and real-world behavioral outcomes such as substance abuse and psychopathology. Here we report age-related changes and longitudinal test-retest stability (TRS) for the Neurocognition battery of the Adolescent Brain and Cognitive Development (ABCD) study, which included the NIH Toolbox (TB) Cognitive Domain and additional memory and visuospatial processing tests administered at baseline (ages 9-11) and two-year follow-up. As expected, performance improved significantly with age, but the effect size varied broadly, with Pattern Comparison and the Crystallized Cognition Composite showing the largest age-related gain (Cohen's d:.99 and.97, respectively). TRS ranged from fair (Flanker test: r = 0.44) to excellent (Crystallized Cognition Composite: r = 0.82). A comparison of longitudinal changes and cross-sectional age-related differences within baseline and follow-up assessments suggested that, for some measures, longitudinal changes may be confounded by practice effects and differences in task stimuli or procedure between baseline and follow-up. In conclusion, a subset of measures showed good stability of individual differences despite significant age-related changes, warranting their use as prospective predictors. However, caution is needed in the interpretation of observed longitudinal changes as indicators of neurocognitive development.

Adolescent Decision-Making Under Risk: Neural Correlates and Sex Differences

An increased propensity for risk taking is a hallmark of adolescent behavior with significant health and social consequences. Here, we elucidated cortical and subcortical regions associated with risky and risk-averse decisions and outcome evaluation using the Balloon Analog Risk Task in a large sample of adolescents (n = 256, 56% female, age 14 ± 0.6), including the level of risk as a parametric modulator. We also identified sex differences in neural activity. Risky decisions engaged regions that are parts of the salience, dorsal attention, and frontoparietal networks, but only the insula was sensitive to increasing risks in parametric analyses. During risk-averse decisions, the same networks covaried with parametric levels of risk. The dorsal striatum was engaged by both risky and risk-averse decisions, but was not sensitive to escalating risk. Negative-outcome processing showed greater activations than positive-outcome processing. Insula, lateral orbitofrontal cortex, middle, rostral, and superior frontal areas, rostral and caudal anterior cingulate cortex were activated only by negative outcomes, with a subset of regions associated with negative outcomes showing greater activation in females. Taken together, these results suggest that safe decisions are predicted by more accurate neural representation of increasing risk levels, whereas reward-related processes play a relatively minor role.

Test-Retest Reliability of Neural Correlates of Response Inhibition and Error Monitoring: An fMRI Study of a Stop-Signal Task

Response inhibition (RI) and error monitoring (EM) are important processes of adaptive goal-directed behavior, and neural correlates of these processes are being increasingly used as transdiagnostic biomarkers of risk for a range of neuropsychiatric disorders. Potential utility of these purported biomarkers relies on the assumption that individual differences in brain activation are reproducible over time; however, available data on test-retest reliability (TRR) of task-fMRI are very mixed. This study examined TRR of RI and EM-related activations using a stop signal task in young adults (n = 56, including 27 pairs of monozygotic (MZ) twins) in order to identify brain regions with high TRR and familial influences (as indicated by MZ twin correlations) and to examine factors potentially affecting reliability. We identified brain regions with good TRR of activations related to RI (inferior/middle frontal, superior parietal, and precentral gyri) and EM (insula, medial superior frontal and dorsolateral prefrontal cortex). No subcortical regions showed significant TRR. Regions with higher group-level activation showed higher TRR; increasing task duration improved TRR; within-session reliability was weakly related to the long-term TRR; motion negatively affected TRR, but this effect was abolished after the application of ICA-FIX, a data-driven noise removal method.

Shared genetic influences on adolescent body mass index and brain structure: A voxel-based morphometry study in twins

BACKGROUND

Previous research has demonstrated significant relationships between obesity and brain structure. Both phenotypes are heritable, but it is not known whether they are influenced by common genetic factors. We investigated the genetic etiology of the relationship between individual variability in brain morphology and BMIz using structural MRI in adolescent twins.

METHOD

The sample (n = 258) consisted of 54 monozygotic and 75 dizygotic twin pairs (mean(SD) age = 13.61(0.505), BMIz = 0.608(1.013). Brain structure (volume and density of gray and white matter) was assessed using VBM. Significant voxelwise heritability of brain structure was established using the Accelerated Permutation inference for ACE models (APACE) program, with structural heritability varying from 15 to 97%, depending on region. Bivariate heritability analyses were carried out comparing additive genetic and unique environment models with and without shared genetics on BMIz and the voxels showing significant heritability in the APACE analyses.

RESULTS

BMIz was positively related to gray matter volume in the brainstem and thalamus and negatively related to gray matter volume in the bilateral uncus and medial orbitofrontal cortex, gray matter density in the cerebellum, prefrontal lobe, temporal lobe, and limbic system, and white matter density in the brainstem. Bivariate heritability analyses showed that BMIz and brain structure share ∼1/3 of their genes and that ∼95% of the phenotypic correlation between BMIz and brain structure is due to shared additive genetic influences. These regions included areas related to decision-making, motivation, liking vs. wanting, taste, interoception, reward processing/learning, caloric evaluation, and inhibition.

CONCLUSION

These results suggested genetic factors are responsible for the relationship between BMIz and heritable BMIz related brain structure in areas related to eating behavior.

Higher Adolescent Body Mass Index Is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM) was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%), in 137 adolescents (age range: 9–20 years, BMI% range: 5.16–99.56). Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ). After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = −0.338, left: r = −0.404), medial prefrontal cortex (partial r = −0.339), anterior cingulate (partial r = −0.312), bilateral frontal pole (right: partial r = −0.368, left: r = −0.316), and uncus (partial r = −0.475) as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = −0.34, left: r = −0.386), extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG) was correlated negatively with BMI% (partial r = −0.384). PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329). These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration.

Identification of sensory attributes, instrumental and chemical measurements important for consumer acceptability of grilled lamb Longissimus lumborum

In this study, important eating quality attributes that influence consumer liking for grilled lamb loin have been identified using preference mapping techniques. The eating quality attributes identified as driving the consumer liking of lamb loin steaks were “tenderness”, “sweet flavour”, “meaty aftertaste”, “roast lamb flavour” and “roast lamb aftertaste”. In contrast, the texture attribute “rubbery” and the flavour attributes “bitter flavour” and "bitter aftertaste" had a negative influence on consumer perceptions. Associations were observed between eating quality and a number of instrumental and chemical measurements. Warner Bratzler Shear Force showed an association with “rubbery” texture and a negative association with “tenderness” and consumer liking scores. The compounds, glucose, glucose-6-phosphate, inosine, inosine monophosphate and adenosine monophosphate were associated with the attributes, “sweet flavour”,“meaty aftertaste”, “roast lamb flavour”, “roast lamb aftertaste” and with consumer scores for liking of lamb which is probably caused by the role some of these compounds play as precursors of flavour and as taste compounds.

Purification and Properties of an S-Adenosylmethionine: 2,4-Disubstituted Phenol O-Methyltransferase from Phanerochaete chrysosporium

An enzyme catalyzing the O-methylation of acetovanillone (3-methoxy-4-hydroxyacetophenone) by S-adeno-sylmethionine was isolated from Phanerochaete chrysosporium and purified 270-fold by ultrafiltration, anion-exchange chromatography, and gel filtration. The enzyme exhibited a pH optimum between 7 and 9 and was rapidly denatured at temperatures above 55 degrees C. The K(m) values for acetovanillone and S-adenosylmethionine were 34 and 99 muM, respectively. S-Adenosylhomocysteine acted as a powerful competitive inhibitor of S-adenosylmethionine, with a K(i) of 41 muM. The enzyme was also susceptible to inhibition by thiol reagents and low concentrations of heavy metal ions. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that the enzyme was monomeric and had a molecular weight of approximately 53,000. Substrate specificity studies showed that 3-methoxy- and 3,5-dimethoxy-substituted 4-hydroxy-benzaldehydes, -benzoic acids, and -acetophenones were the preferred substrates for the enzyme. The corresponding 3,4-dihydroxy compounds were methylated relatively slowly, while the 3-hydroxy-4-methoxy compounds were almost inactive as substrates. Substituents in both the 2 and 4 positions relative to the hydroxyl group appeared to be essential for significant enzyme attack of a substrate. Provided that certain steric criteria were satisfied, the nature of the substituent was not critical. Hence, xenobiotic compounds such as 2,4-dichlorophenol and 2,4-dibromophenol were methylated almost as readily as acetovanillone. However, an extended side chain in the 4 position was not compatible with activity as a substrate, and neither homovanillic, caffeic, nor ferulic acid was methylated. The substrate range of the O-methyltransferase tends to imply a role in the catabolism or detoxification of lignin degradation products such as vanillic and syringic acids.

Voice outcomes following transoral laser microsurgery for early glottic squamous cell carcinoma

INTRODUCTION

Early glottic cancer may be treated with primary radiotherapy or transoral laser microsurgery with comparable survival. The choice of therapy therefore depends on patient preference after discussion of risks, benefits and alternatives.

MATERIALS AND METHODS

All previously untreated patients undergoing transoral laser microsurgery for T1 or T2 glottic cancer at St Vincent's Hospital between July 1997 and December 2004 had their staging and demographics recorded. Surgery was categorised according to the European Laryngological Society. A voice recording was made pre-operatively then at 12 weeks post-operatively and scored by two independent speech therapists on the Oates Russell Voice Profile - a scale of zero (normal) to five (severe dysphonia). Follow up was for a minimum of two years.

RESULTS AND ANALYSIS

Fifty-three patients with a mean age of 56 were included. The observed survival was T1 89.4 per cent and T2 85.3 per cent after a mean follow up of 47 months. Nineteen patients staged T1 underwent cordectomy. A second procedure was required in 22.2 per cent, however, none required a laryngectomy. Thirty-four patients staged T2 underwent hemilaryngectomy. A second procedure was required in 41.2 per cent including 8.8 per cent requiring salvage laryngectomy. One patient died with unresectable nodal disease. The mean Oates Russell Voice Profile for T1 disease was 2.37 and for T2 2.68 (range 1 to 4) indicating a mild (2) to moderate (3) degree of voice impairment.

CONCLUSIONS

Survival outcomes following transoral laser microsurgery are comparable to treatment with radiotherapy. Voice impairment is usually mild to moderate following transoral laser microsurgery for early glottic cancer but overall may be greater than in radiotherapy patients. The repeatability of transoral laser microsurgery may result in a lower laryngectomy rate compared with published series using radiotherapy.

The distinctive isotopic signature of plant-derived chloromethane: possible application in constraining the atmospheric chloromethane budget

Chloromethane (CH(3)Cl) is the most abundant halocarbon in the atmosphere. Although largely of natural origin it is responsible for around 17% of chlorine-catalysed ozone destruction. Sources identified to date include biomass burning, oceanic emissions, wood-rotting fungi, higher plants and most recently tropical ferns. Current estimates reveal a shortfall of around 2 million ty(-1) in sources versus sinks for the halocarbon. It is possible that emissions from green plants have been substantially underestimated. A potentially valuable tool for validating emission flux estimates is comparison of the delta13C value of atmospheric CH(3)Cl with those of CH(3)Cl from the various sources. Here we report delta13C values for CH(3)Cl released by two species of tropical ferns and show that the isotopic signature of CH(3)Cl from pteridophytes like that of CH(3)Cl from higher plants is quite different from that of CH(3)Cl produced by biomass burning, fungi and industry. delta13C values for CH(3)Cl produced by Cyathea smithii and Angiopteris evecta were respectively -72.7 per thousand and -69.3 per thousand representing depletions relative to plant biomass of 42.3 per thousand and 43.4 per thousand. The characteristic isotopic signature of CH(3)Cl released by green plants should help constrain their contribution to the atmospheric burden when reliable delta13C values for all other major sources of CH(3)Cl are obtained and a globally averaged delta13C value for atmospheric CH(3)Cl is available.

Continuous flow stable isotope methods for study of delta(13)C fractionation during halomethane production and degradation

Gas chromatography/mass spectrometry/isotope ratio mass spectrometry (GC/MS/IRMS) methods for delta(13)C measurement of the halomethanes CH(3)Cl, CH(3)Br, CH(3)I and methanethiol (CH(3)SH) during studies of their biological production, biological degradation, and abiotic reactions are presented. Optimisation of gas chromatographic parameters allowed the identification and quantification of CO(2), O(2), CH(3)Cl, CH(3)Br, CH(3)I and CH(3)SH from a single sample, and also the concurrent measurement of delta(13)C for each of the halomethanes and methanethiol. Precision of delta(13)C measurements for halomethane standards decreased (+/-0.3, +/-0.5 and +/-1.3 per thousand) with increasing mass (CH(3)Cl, CH(3)Br, CH(3)I, respectively). Given that carbon isotope effects during biological production, biological degradation and some chemical (abiotic) reactions can be as much as 100 per thousand, stable isotope analysis offers a precise method to study the global sources and sinks of these halogenated compounds that are of considerable importance to our understanding of stratospheric ozone destruction.

Comparison of the Efficacies of Chloromethane, Methionine, and S-Adenosylmethionine as Methyl Precursors in the Biosynthesis of Veratryl Alcohol and Related Compounds in Phanerochaete chrysosporium

The effect on veratryl alcohol production of supplementing cultures of the lignin-degrading fungus Phanerochaete chrysosporium with different methyl-(sup2)H(inf3)-labelled methyl precursors has been investigated. Both chloromethane (CH(inf3)Cl) and l-methionine caused earlier initiation of veratryl alcohol biosynthesis, but S-adenosyl-l-methionine (SAM) retarded the formation of the compound. A high level of C(sup2)H(inf3) incorporation into both the 3- and 4-O-methyl groups of veratryl alcohol occurred when either l-[methyl-(sup2)H(inf3)]methionine or C(sup2)H(inf3)Cl was present, but no significant labelling was detected when S-adenosyl-l-[methyl-(sup2)H(inf3)]methionine was added. Incorporation of C(sup2)H(inf3) from C(sup2)H(inf3)Cl was strongly antagonized by the presence of unlabelled l-methionine; conversely, incorporation of C(sup2)H(inf3) from l-[methyl-(sup2)H(inf3)]methionine was reduced by CH(inf3)Cl. These results suggest that l-methionine is converted either directly or via an intermediate to CH(inf3)Cl, which is utilized as a methyl donor in veratryl alcohol biosynthesis. SAM is not an intermediate in the conversion of l-methionine to CH(inf3)Cl. In an attempt to identify the substrates for O methylation in the metabolic transformation of benzoic acid to veratryl alcohol, the relative activities of the SAM- and CH(inf3)Cl-dependent methylating systems on several possible intermediates were compared in whole mycelia by using isotopic techniques. 4-Hydroxybenzoic acid was a much better substrate for the CH(inf3)Cl-dependent methylation system than for the SAM-dependent system. The CH(inf3)Cl-dependent system also had significantly increased activities toward both isovanillic acid and vanillyl alcohol compared with the SAM-dependent system. On the basis of these results, it is proposed that the conversion of benzoic acid to veratryl alcohol involves para hydroxylation, methylation of 4-hydroxybenzoic acid, meta hydroxylation of 4-methoxybenzoic acid to form isovanillic acid, and methylation of isovanillic acid to yield veratric acid.

Wegener's granulomatosis: clinical features and prognosis in 37 patients

Thirty-seven patients (21 female, 16 male) with Wegener's granulomatosis (WG) were reviewed. Patients were followed for a mean six years after diagnosis; 14 were followed for more than seven years. The clinical features were similar to those in previous studies. In this series, only 13 patients (35%) had renal disease at presentation and the cumulative incidence of renal involvement was 51%. Thirty-one patients received treatment which included cyclophosphamide (CP). The case fatality rate of the six patients not treated with CP was 83% (five deaths). By contrast, all CP treated patients improved and 21 (68%) had complete remissions. Nine (29%) were in complete remission for a mean 4.9 years after discontinuing all treatment. Two were disease free for over ten years. The actuarial probability of survival for these patients was 97% at one year and 71% at ten years. Only three CP treated patients (10%) progressed to end-stage renal disease. The case fatality rate was 26% (eight patients) and sepsis was the cause of death in five. Fourteen patients (45%) treated with CP had at least one relapse of vasculitis and seven (23%) had multiple (two or more) relapses. These data indicate that CP is effective in inducing remissions and prolonging survival in patients with WG; however, relapses are frequent.

Papillary carcinoma arising in ectopic thyroid tissue within a branchial cyst

The first case of a papillary carcinoma arising in ectopic thyroid tissue within a branchial cyst in a 34 yr old woman is presented. This also adds to the existing list of unusual sites where ectopic thyroid tissue has been described. All histological types of carcinoma have been reported in ectopic thyroid tissue, papillary carcinoma being the most common histological type, accounting for 85% of these tumors. The criteria for establishing this diagnosis of carcinoma arising in ectopic thyroid tissue within branchial cyst is discussed.

HIV seroprevalence in a facility for runaway and homeless adolescents

In October 1987, the New York State Department of Health initiated a study to determine the prevalence of antibody to HIV in clients of a facility for runaway and homeless adolescents in New York City. A risk-assessment component was added in May 1988. As of December 1989, a total of 2,667 adolescents had been tested, and 142 (5.3 percent) were found to be HIV-seropositive (males 6.0 percent, females 4.2 percent). The seroprevalence rate increased from 1.3 percent for 15-year-olds to 8.6 percent for 20-year-olds. Hispanics had the highest seroprevalence rate (6.8 percent), followed by non-Hispanic Whites (6.0 percent) and non-Hispanic Blacks (4.6 percent). HIV seropositivity was associated with intravenous drug use, male homosexual/bisexual activity, prostitution, and history of another sexually transmitted disease. The alarmingly high prevalence of HIV infection in this selected population illustrates the immediate need for prevention programs for adolescents.

Chloromethane, Methyl Donor in Veratryl Alcohol Biosynthesis in Phanerochaete chrysosporium and Other Lignin-Degrading Fungi

Chloromethane, a gaseous natural product implicated in methylation processes in Phellinus pomaceus , has been shown to act as methyl donor in veratryl alcohol biosynthesis in the lignin-degrading fungi Phanerochaete chrysosporium, Phlebia radiata , and Coriolus versicolor , none of which released detectable amounts of CH 3 Cl during growth. When P. chrysosporium was grown in a medium containing C 2 H 3 Cl, levels of C 2 H 3 incorporation into the 3- and 4- O -methyl groups of veratryl alcohol were very high and initially similar to those observed when the medium was supplemented with l -[ methyl - 2 H 3 ]methionine. When C 2 H 3 Cl was added to cultures actively synthesizing veratryl alcohol, incorporation of C 2 H 3 was very rapid, with 81% of veratryl alcohol labeled after 12 h. By contrast, incorporation of C 2 H 3 from l -[ methyl - 2 H 3 ]methionine was comparatively slow, attaining 10% after 12 h. It is proposed that these lignin-degrading fungi possess a tightly channeled multienzyme system in which CH 3 Cl biosynthesis is closely coupled to CH 3 Cl utilization for methylation of veratryl alcohol precursors.

Chloromethane, a Novel Methyl Donor for Biosynthesis of Esters and Anisoles in Phellinus pomaceus

Chloromethane (CH 3 Cl), a gaseous natural product released as a secondary metabolite by many woodrotting fungi of the family Hymenochaetaceae , has been shown to act as a methyl donor for biosynthesis of methyl esters of benzoic and furoic acid in the primary metabolism of Phellinus pomaceus. The broad-specificity methylating system could esterify a wide range of aromatic and aliphatic acids. In addition to CH 3 Cl, both bromo- and iodomethanes acted as methyl donors. Methylation did not appear to proceed via methanol or a coenzyme A intermediate. The initial growth-related accumulation of methyl benzoate during culture of P. pomaceus was paralleled by an increase in activity of the methylating system in the mycelium. Changes in percent incorporation of C 2 H 3 from exogenous C 2 H 3 Cl during growth indicated that although utilization of CH 3 Cl was initially closely coupled to biosynthesis of the compound, the system became less tightly channeled later in growth. This phase coincided with release of gaseous CH 3 Cl by the fungus. A biochemically distinct CH 3 Cl-utilizing system capable of methylating phenols and thiophenol was also identified in the fungus, but in contrast with the carboxylic acid-methylating system, it attained maximum activity in the idiophase. Preliminary investigations of a non-CH 3 Cl-releasing fungus, Fomitopsis pinicola , have shown the presence of a CH 3 Cl-utilizing system capable of methylating benzoic acid, suggesting that CH 3 Cl biosynthesis may occur in non-hymenochaetaceous fungi. Halogenated compounds hitherto found in nature are mainly stable end products of metabolism. The participation of CH 3 Cl in primary fungal metabolism demonstrates that some halometabolites may have a previously unrecognized role as intermediates in the biosynthesis of nonhalogenated natural products.

Lethal skin cancers in hairy cell leukemia (two case reports)

2 patients with hairy cell leukemia (HCL) complicated by multiple cutaneous and other malignancies are described. The second malignancies behaved in a much more aggressive fashion than would be expected in an immunocompetent population, and were lethal in both patients. The literature regarding second malignancies in immune compromised patients, and in HCL in particular, is reviewed.

Purification and properties of S-adenosylmethionine: aldoxime O-methyltransferase from Pseudomonas sp. N.C.I.B. 11652

An enzyme catalysing the O-methylation of isobutyraldoxime by S-adenosyl-L-methionine was isolated from Pseudomonas sp. N.C.I.B. 11652. The enzyme was purified 220-fold by DEAE-cellulose chromatography, (NH4)2SO4 fractionation, gel filtration on Sephadex G-100 and chromatography on calcium phosphate gel. Homogeneity of the enzyme preparation was confirmed by isoelectric focusing on polyacrylamide gel and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The enzyme showed a narrow pH optimum at 10.25, required thiol-protecting agents for activity and was rapidly denatured at temperatures above 35 degrees C. The Km values for isobutyraldoxime and S-adenosyl-L-methionine were respectively 0.24 mM and 0.15 mM. Studies on substrate specificity indicated that attack was mainly restricted to oximes of C4-C6 aldehydes, with preference being shown for those with branching in the 2- or 3-position. Ketoximes were not substrates for the enzyme. Gel filtration on Sephadex G-100 gave an Mr of 84 000 for the intact enzyme, and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis indicated an Mr of 37 500, suggesting the presence of two subunits in the intact enzyme. S-Adenosylhomocysteine was a powerful competitive inhibitor of S-adenosylmethionine, with a Ki of 0.027 mM. The enzyme was also susceptible to inhibition by thiol-blocking reagents and heavy-metal ions. Mg2+ was not required for maximum activity.

The importance of tumor attachment to the carotid artery

The records of 508 patients who had undergone radical neck dissection were reviewed. Twenty-eight of these patients (5.5%) were found to have tumor attached to the carotide arterial system. Twenty-four patients (86%) died with tumor, the mean survival time being 16.9 months. Local recurrence of tumor in the neck occurred in 46% of the patients and distant metastases in 67%. Eighteen percent of those who developed local recurrence did so in the absence of distant metastases and might have benefited from a more aggressive approach toward the tumor.

A search for common tumor specific antigen and serum blocking factor in head and neck epidermoid carcinomas

In vitro, colony inhibition tests using lymphocytes and serum from 42 patients with other carcinomas, and 12 control patients with no carcinoma, were performed using cultured target cells (CALI). Target cell colony counts were significantly diminished by lymphocytes of 2 of 12 (16.7 percent) patients with no cancer, compared with those 26 of 42 (61.9 percent) patients with epidermoid carcinoma. An unexpected finding was significant colony inhibition of lymphocytes of 23 of 27 (85.2 percent) patients tested within 24 months of diagnosis of carcinoma compared with significant inhibition in only 3 of 15 (20 percent) patients tested after 24 months of diagnosis of carcinoma. Serum blocking factor was found in 9 of 42 (21.4 percent) patients with epidermoid carcinoma. It was found on follow-up that four of these nine (44.4 percent) had later recurrent or new tumors compared to recurrence or new tumor incidence of only 6 of 33 (18.2 percent) patients with no serum blocking factor present in the serum.

Ardomino-anal pull-through resection of the rectum

Three independent observers have surveyed the results in 158 patients treated by abdomino-anal pull-through excision of the rectum and reached the following conclusions:— The operative mortality of the procedure (4·5 per cent) was low and quite comparable with that following alternative methods of rectal excision.The operation compares favourably with anterior resection and combined excision as a cancer-curing procedure for growths similarly sited in the rectum.Some degree of morbidity following operation occurred in almost half the patients, but significant complications occurred in only about 20 per cent. Colonic necrosis (4·6 per cent) and pelvic sepsis (18 per cent) were the most important. Permanent colostomies were ultimately established in 6 per cent of patients.In the majority of patients the operation was ultimately compatible with good anorectal function. Continence usually improved after about 1 year, though adequate control was often achieved within 6 months. Of those patients with stable bowel function at the time of interview, 89 per cent had a satisfactory result.