Middle and Later Stone Age large mammal and tortoise remains from Die Kelders Cave 1, Western Cape Province, South Africa

Die Kelders Cave 1, South Africa, has provided more than 150,000 taxonomically identifiable mammal and tortoise bones from Middle Stone Age (MSA) and Later Stone Age (LSA) deposits. Cape dune mole-rats dominate the mammal sample, and they appear to have been accumulated mainly by people during the LSA occupation and mainly by eagle owls in the MSA. In sharp contrast to the LSA fauna, the MSA sample contains extralimital ungulates that imply relatively moist, grassy conditions. The large mean size of the MSA mole-rats also points to greater humidity, while the large size of the gray mongooses implies cooler temperatures. The sum supports luminescence and ESR dates that place the MSA occupation within the early part of the Last Glaciation (global isotope stage 4). The Die Kelders ungulate bones support those from Klasies River Mouth in suggesting that MSA people obtained dangerous terrestrial prey much less frequently than their LSA successors, probably because MSA people lacked the bow and arrow and other projectile weapons. The Die Kelders tortoise bones constrain the extent of climatic change, since their abundance indicates that warm, dry days remained common, at least seasonally. The tortoises tend to be much larger in the MSA layers than in the LSA ones, suggesting that MSA people collected tortoises less intensively, probably because MSA populations were relatively sparse.

Duinefontein 2: an Acheulean site in the Western Cape Province of South Africa

Excavations at Duinefontein (DFT) 2 near Cape Town, South Africa have recovered numerous stone artefacts and animal bones on an ancient surface sealed within iron-stained eolian sands. U-series analysis of an overlying calcrete places the sands before 150 ka ago, while the large mammal taxa imply an age between 400 and 200 ka ago. The artefacts include a classic Acheulean handaxe and probable biface shaping flakes that support this age estimate. The principal mammalian species are long-horned buffalo, black wildebeest, greater kudu, Cape zebra, and grysbok/steenbok, which imply a grass-and-bush mosaic instead of the historic small-leafed shrubland. Hippopotamus and reedbuck indicate that water stood nearby, probably in dune swales. The large mammal bones are mostly vertebrae and other axial elements, often in near-anatomical order. Both proximal and distal appendicular elements are rare. Bones with carnivore damage are common, but ones with stone tool marks are scarce. The sum suggests a water-edge attritional death site where people played a minimal role and carcasses were disarticulated mainly by carnivore feeding and by trampling. Stone tool marks tend to be equally rare at other Acheulean attritional death sites, and the implication may be that Acheulean people rarely obtained large mammals, whether by hunting or scavenging. Human scavengers at DFT2 would not have encountered a disproportionate number of distal (versus proximal) limb elements, and it follows that the tendency for distal elements to dominate many archeological assemblages need not reflect scavenging versus hunting. Even if DFT2 was not itself a locus of intense human activity, it provides a useful baseline for evaluating bone damage, skeletal part representation, and other variables at sites where people were deeply involved.

Strong nasal carcinogenicity and genotoxicity of 1-nitroso-4-methylpiperazine after low dose inhalation in rats

Sprague-Dawley rats were exposed by inhalation to 1-nitroso-4-methylpiperazine (NMPz) vapor at 2.4 p.p.m. for 15 h/day for 74 days over a 7.5 month period. After a dose of 1.1 mg/day NMPz (total dose 340 mg/kg body wt) 10/10 animals developed tumors of the nasal cavity, mostly invasive muco-epidermoidal carcinomas; no such tumors were observed in sham-exposed controls. This high tumor yield was seen at an 80 times lower dose and a shorter latency period when compared with rat carcinogenicity studies reported earlier. The single cell microgel electrophoresis (Comet) assay was used to determine genotoxicity in target tissues. Short-term in vitro exposure of rat and human nasal epithelial tissues to NMPz caused genotoxic effects in cells of both species. Short-term in vivo exposure of rats to NMPz vapor for 1 h induced DNA damage in nasal epithelial cells. Our results revealed NMPz as a potent genotoxic nitrosamine in rat and human nasal cells, the carcinogenicity of inhaled NMPz vapor in rats being remarkably higher as compared with oral uptake.

Nickel subsulfide is genotoxic in vitro but shows no mutagenic potential in respiratory tract tissues of BigBlue rats and Muta Mouse mice in vivo after inhalation

Carcinogenic nickel compounds are known to induce promutagenic DNA lesions such as DNA strand breaks and DNA adducts in cultured mammalian cells. In standard mutation assays, in contrast, they were found to be either inactive or weakly active. In our in vitro mutation studies in a lacI transgenic embryonic fibroblast cell line, nickel subsulfide (Ni3S2) increased mutation frequency up to 4. 5-fold. We subsequently applied the comet assay and transgenic rodent mutation assays to investigate the DNA damaging effect and mutagenic potential of nickel subsulfide in target cells of carcinogenesis. A 2-h in vitro treatment of freshly isolated mouse nasal mucosa and lung cells with nickel subsulfide clearly induced DNA fragmentation in a concentration dependent manner. The strong effect was not seen in the same cell types following inhalative treatment of mice and rats, leading only in the mouse nasal mucosa to high DNA damage. When the same inhalative treatment was applied to lacZ and lacI transgenic mice and rats, the spontaneous mutation frequency of these target genes in the respiratory tissues was not increased. These results support a recently proposed non-genotoxic model of nickel carcinogenesis, which acts through gene silencing via DNA methylation and chromatin condensation. This model may also explain our in vitro mutation data in the lacI transgenic cell line, in which nickel subsulfide increased mutation frequency, but in about one-third of the mutants, molecular analysis did not reveal any DNA sequence change in the coding region of the lacI gene despite of the phenotypic loss of its function.

Mutagenic activity of carcinogens detected in transgenic rodent mutagenicity assays at dose levels used in chronic rodent cancer bioassays

Data on transgenic rodent mutagenicity of five human carcinogens were summarised and compared with the results from rodent carcinogenicity studies. Four out of five carcinogens showed mutagenic activity already at daily dose levels which induced cancer in long-term rodent bioassays in at least one target tissue of carcinogenesis. In several of these studies, even single dose applications were sufficient to significantly increase the mutation frequency in vivo. Other genotoxic carcinogens required application of multiple dosing at dose-levels used in rodent cancer bioassays to show their in vivo mutagenicity. A rodent respiratory tract carcinogen, 1,2-dibromoethane (DBE), following inhalation exposure, displayed no mutagenic activity, neither in lung nor in nasal mucosa, at a single 2-h exposure to 30 ppm, which is below the highest concentration used in a NTP cancer bioassay. In contrast, after multiple treatment for 10 days at the same daily doses, a significant increase of the mutation frequency in nasal mucosa was apparent. We conclude, that especially when studying new chemicals in these transgenic rodent mutation assays, a multiple dosing protocol should be preferred. For dose selection, the same criteria could be applied as for chronic rodent bioassays.

Additional human fossils from Klasies River Mouth South Africa

A fragmentary temporal bone and partial atlas from the Middle Stone Age (MSA) at Klasies River Mouth (KRM) are described and analyzed. The atlas (SAM-AP 6268) is comparable to Levantine "Early Modern", Neandertal and recent human vertebrae. The temporal (SAM-AP 6269) is similar to recent African homologues except that the posteromedial wall of the glenoid fossa is composed entirely of the squamous temporal, a situation that appears to be infrequent among other Pleistocene fossils. The KRM glenoid fossa is also mediolateraly broad and anteroposteriorly short in comparison with many, but not, all recent specimens. Nevertheless, the KRM temporal is decidedly modern, both morphologically and metrically, by comparison with other Pleistocene specimens. The limited evidence provided by this bone is consistent with that of other MSA cranial remains from this site in suggesting an overall, if somewhat ambiguous pattern of morphological modernity.

Adult psychiatric status of hyperactive boys grown up

OBJECTIVE

Numerous studies have examined the adolescent and young adult fate of children with attention deficit hyperactivity disorder (ADHD). In marked contrast, relatively little is known about the adult outcome of these children. There have been only two controlled, prospective studies of psychiatric status into adulthood. The present study was conducted to gain further understanding of the natural course of this common childhood condition.

METHOD

This was a prospective follow-up of clinically diagnosed, white boys of average intelligence who were referred by teachers to a child psychiatric research clinic at an average age of 7.3 years. At a mean age of 24.1 years, 85 probands (82% of the childhood cohort) and 73 comparison subjects (94% of adolescent comparison subjects) were directly interviewed by trained clinicians who were blind to group status.

RESULTS

Evaluations of the probands and comparison subjects indicated significantly higher prevalences of antisocial personality disorder (12% versus 3%) and nonalcohol substance abuse (12% versus 4%) in the probands, whereas mood disorders (4% versus 4%) and anxiety disorders (2% versus 7%) were not significantly different. At adult follow-up, ADHD was rare, occurring in only 4% of the probands (no comparison subjects).

CONCLUSIONS

The results of the present study are consistent with the authors' previously reported major findings. They strongly suggest that children with ADHD are at significantly higher risk for a specific negative course marked by antisocial and substance-related disorders.

Ventilatory physiology of children and adolescents with anxiety disorders

BACKGROUND

Abnormalities in ventilatory physiology have been noted in adults with panic disorder. We tested the hypothesis that abnormalities in ventilatory physiology differentiate children and adolescents with anxiety disorders from psychiatrically healthy children.

METHODS

Ventilatory physiology was monitored with a canopy apparatus during room-air breathing and 15 minutes of carbon dioxide exposure in 33 children and adolescents comprising 18 probands with an anxiety disorder and 15 psychiatrically healthy children.

RESULTS

During room-air breathing, probands had significantly larger minute ventilation, larger tidal volumes, and more variable breathing patterns than healthy comparisons, but the groups did not differ in end-tidal carbon dioxide or respiratory rate. During carbon dioxide challenge, probands exhibited larger minute ventilation and respiratory rate responses relative to comparisons.

CONCLUSION

These findings on the association between ventilatory physiology and anxiety disorders in children and adolescents are consistent with results from studies of adults with panic disorder.

Use of transgenic mutational test systems in risk assessment of carcinogens

Two transgenic in vivo mutation assays are described which are based on LacZ (Muta Mouse) and LacI (Big Blue) shuttle vector systems. Their utility has already been explored by a number of investigators including our laboratory. The evaluation of data derived from these assays confirm that they offer a practical method for studying mutagenic activity and mechanism in a wide range of tissues including those of the respiratory and gastrointestinal tract. Therefore, these transgenic mutation assays are valuable tools to assess the organotropic effects of genotoxic carcinogens.

Clinical efficacy of methylphenidate in conduct disorder with and without attention deficit hyperactivity disorder

BACKGROUND

Stimulants are not considered appropriate for the treatment of children with conduct disorders (CDs). The postulated differences in stimulant effect between children with attention deficit hyperactivity disorder (ADHD) and CD led to the hypothesis that methylphenidate hydrochloride, which is effective in ADHD, would not significantly improve symptoms of CD.

METHODS

We randomly assigned 84 children with CD, between the ages of 6 and 15 years, to receive methylphenidate hydrochloride (up to 60 mg/d) or placebo for 5 weeks. Behavior was evaluated by parent, teacher, and clinician reports and by direct classroom observations. Two thirds of the children also met criteria for ADHD.

RESULTS

Contrary to prediction, ratings of antisocial behaviors specific to CD were significantly reduced by methylphenidate treatment. The magnitude of methylphenidate effect indicated meaningful clinical benefit. Partialling out severity of ADHD did not alter the significant superiority of methylphenidate on CD ratings specifically (P < .001).

CONCLUSIONS

Methylphenidate has short-term positive effects on children and adolescents with CD. Key aspects of antisocial adjustment appear to be treatment responsive. This effect was independent of severity of the children's initial ADHD symptoms.

Test-retest reliability of maternal reports of lifetime mental disorders in their children

This study examined the test-retest reliability of maternal reports of lifetime psychopathology using DSM-III-R criteria in nonreferred offspring. Sixty-three mothers reported on 79 children, ages 6 to 18 years. Retest intervals were between one and 12 months. The results indicated acceptable reliability for all supraordinate categories (any disorder, any anxiety disorder, any disruptive disorder, externalizing disorders, internalizing disorders) as well as for most individual diagnoses (separation anxiety disorder, simple phobias, oppositional defiant disorder, attention deficit disorder with and without hyperactivity, simple phobias, and adjustment disorder). Maternal reports for any diagnosis were significantly better for intervals under 6 months than for longer retest intervals. Reliability of maternal reports was not significantly affected by child's age or gender. This study supports the expectation that a history of psychiatric disturbance in children can be obtained reliably from mothers.

Educational and occupational outcome of hyperactive boys grown up

OBJECTIVE

Little is known about the adult outcome of attention-deficit hyperactivity disorder (ADHD), a very prevalent childhood disorder that is known to affect deleteriously academic performance and other areas of child functioning. This study represents a third wave of evaluations that examine the long-term educational achievement and occupational rank of children with ADHD.

METHOD

This is a prospective follow-up of white boys of average intelligence whose ADHD was clinically diagnosed according to systematic criteria at an average age of 7 years. Follow-up intervals range from 15 to 21 years (mean, 17 years). At average age 24 years, 85 probands (representing 82% of the childhood cohort) and 73 controls (84%) were directly interviewed by trained clinicians who were blind to group membership.

RESULTS

First, probands completed significantly less formal schooling than controls (about 2 years less, on average). Second, probands had lower-ranking occupational positions than controls. Finally, these disadvantages were not accounted for by adult mental status.

CONCLUSIONS

The present study suggests that childhood ADHD predisposes to specific disadvantages and continues to affect important functional domains unrelated to current psychiatric diagnosis.

Systematic assessment of 50 children with selective mutism

OBJECTIVE

To clarify the diagnostic significance of selective mutism (elective mutism in DSM-III-R).

METHOD

Fifty children with selective mutism were evaluated systematically by means of semistructured clinical interviews and rating scales to obtain detailed diagnostic information.

RESULTS

All 50 children met DSM-III-R criteria for social phobia or avoidant disorder and 24 (48%) had additional anxiety disorders. Clinical measures of anxiety and behavioral symptoms supported the presence of anxiety disorders as a characteristic of selectivity mute children. Only one case each of oppositional defiant disorder and attention-deficit hyperactivity disorder was found.

CONCLUSIONS

Persistent selective mutism typically presents in the context of anxiety disorders.

Teacher ratings of hyperactivity, inattention, and conduct problems in preschoolers

Age and sex norms of classroom behavior in preschoolers were established on a standard measure, the Revised Conners Teacher Rating Scale, and the utility of this measure for assessing problem behavior in preschoolers was examined. Teachers provided ratings for 455 nonreferred preschoolers. In addition, ratings were obtained for 12 clinically referred preschoolers diagnosed with attention deficit hyperactivity disorder. The Conduct Problems, Inattention, and Hyperactivity subscales, as well as the Hyperactivity Index, were found to have good internal reliability and were related to each other in predictable ways. Normative data are presented by age and sex. Age was inversely related to scores for the Conduct Problems subscale, the Hyperactivity subscale and the Index. Sex was a significant predictor of subscale scores, with boys receiving higher scores than girls. Subscale scores and nearly all item scores were highly significantly different between clinically referred and nonreferred preschoolers. The results provide a standard upon which to evaluate preschool-aged children in clinical and research settings.

Transport of reactive metabolites of procarcinogens between different liver cell types, as demonstrated by the single cell microgel electrophoresis assay

Procarcinogens have to be activated by specific cytochromes before showing adverse effects. Freshly isolated hepatocytes (parenchymal liver cells, PC) are characterized by a high content of such xenobiotic enzymes and are widely used to investigate chemically induced DNA damage. But in many cases liver tumors caused by indirect acting carcinogens can also originate from non-parenchymal liver cells (NPC). We used freshly isolated rat PC and NPC to demonstrate that only PC have activation capacity when treated in vitro with different genotoxic procarcinogens (N-nitrosodimethylamine, NDMA; vinyl chloride, VC). The alkaline single cell microgel electrophoresis assay was applied to measure the genotoxic activity of the activated compounds. In order to test the hypothesis that reactive metabolites can be transported from PC to NPC, we performed additional in vivo studies as well as studies in which PC were incubated together with NPC, only separated by a dialysis tube (in vitro coincubation). The results indicate that reactive metabolites of both NDMA and VC are stable enough to be transported intercellularly from PC to NPC.

Fluoxetine treatment of children with selective mutism: an open trial

OBJECTIVE

A pilot study was designed to evaluate the safety and efficacy of fluoxetine treatment for children with selective mutism (elective mutism in DSM-III-R).

METHOD

Twenty-one children (mean age 8.2 years, range 5 through 14) participated in a 9-week open trial of fluoxetine in graduated doses (mean end dose 28.1 mg, range 10 to 60 mg) with systematic baseline and outcome evaluations and weekly clinical assessment.

RESULTS

All 21 children met DSM-III-R and DSM-IV criteria for anxiety disorders. After fluoxetine treatment, 76% were improved, with diminished anxiety and increased speech in public settings, including school. Improvement at week 9 was inversely correlated with age.

CONCLUSIONS

Persistent selective mutism presenting with comorbid anxiety disorders may respond to fluoxetine treatment.

Comments on expanding the clinical role of psychologists

The interest by psychologists in prescription privileges is welcome because it is a manifestation of the long overdue acknowledgement of the efficacy of medication for many mental disorders. The lack of national academic standards in psychology, however, poses a problem. Psychologists are certified in title only and are not licensed to perform any procedure, although there have been efforts to standardize the training of psychologists. Currently, states regulate the title, but no national educational standards exists. Therefore, psychologists are not able to claim they are a homogeneous patient care resource.

Is self-esteem an important outcome in hyperactive children?

Using a prospective design, this study examined (a) whether hyperactive children suffer from low self-esteem as adolescents; (b) whether low self-esteem is associated with poor functioning in adolescence; (c) whether hyperactive children exhibit a positive illusory bias, in which self-esteem is independent of level of functioning; and (d) whether self-esteem in adolescence is associated with poor functioning in adulthood. Subjects were 65 children diagnosed as hyperactive in childhood, and 62 matched controls sampled from a medical clinic. After controlling for current mental disorder, the hyperactive cohort reported lower self-esteem in adolescence, was judged by clinicians to have lower levels of overall adjustment in adolescence, and had lower educational achievement and occupational rank in adulthood, as compared to controls.

Dating and context of three middle stone age sites with bone points in the Upper Semliki Valley, Zaire

The extent to which the earliest anatomically modern humans in Africa exhibited behavioral and cognitive traits typical of Homo sapiens sapiens is controversial. In eastern Zaire, archaeological sites with bone points have yielded dates older than 89(-15)+22 thousand years ago by several techniques. These include electron spin resonance, thermoluminescence, optically stimulated luminescence, uranium series, and amino acid racemization. Faunal and stratigraphic data are consistent with this age.

The New York Teacher Rating Scale for disruptive and antisocial behavior

OBJECTIVE

A teacher rating scale designed to reflect current diagnostic descriptors of oppositional defiant disorder and conduct disorder was developed and standardized.

METHOD

Teacher ratings were obtained for 1,258 1st-through 10th-grade children from two school districts in New York and for 81 clinically referred children with conduct disorder.

RESULTS

Three factors relevant to oppositional defiant disorder and conduct disorder were generated: defiance, physical aggression, and delinquent aggression. A fourth factor reflects peer problems. Internal consistency, test-retest reliability, and interrater reliability are documented using a population and a conduct disorder sample. The validity of the factors is supported by the factors' ability to discriminate between children in the general population and those with conduct disorders, by correlations with global impairment items, and by expected sex differences.

CONCLUSION

The scale has utility for assessing symptoms of conduct disorder in school settings.