A technique for establishing the identity of 'isolated' fossil hominin limb bones

Associated skeletons, which are specimens preserving more than one body part from the same individual, are especially important for taxonomic and functional analyses. This study concentrates on the subset of associated skeletons which preserve the reciprocal surfaces of a joint. It uses laser scanning to explore whether the shapes of the reciprocal surfaces of a joint of an individual are significantly more congruent than the surfaces of randomly-matched pairings taken from the same species. Laser scanning was used to capture the distal articular surface of the left tibia of OH35 and the trochlear articular surface of the talus of OH8, both from Bed I, Olduvai Gorge, Tanzania. The degree of congruency between those articular surfaces was tested against the congruency of the talocrural joint of AL 288-1 (Australopithecus afarensis), and the congruency of both associated and randomly-matched talocrural joints of modern humans, chimpanzees and gorillas. The results suggest that OH35 and OH8 do not come from the same individual and may not come from the same species. Although this analysis leaves open the taxonomic affinity of OH35, it demonstrates the potential of laser scanning for capturing 3D data in palaeoanthropology. It also demonstrates the potential for using the relative congruency of reciprocal joint surfaces as a test of the likelihood that isolated limb bones are components of a single individual.

Teaching the clinical interpretation of peripheral blood smears to a second-year medical school class using the PeripheralBlood-Tutor computer program

The interpretation of peripheral blood smears has an important role in the diagnosis of hematologic diseases and is, therefore, part of the education of physicians and technologists. We describe a computer program, PeripheralBlood-Tutor (Lippincott-Raven, Philadelphia, Pa), that teaches the morphologic features of normal and abnormal peripheral blood smears; we also describe the evaluation of the effectiveness of the program in 133 second-year medical students who were required to use the program in their hematology course. The version of the PeripheralBlood-Tutor used in the study had 2 distinct but equivalent 20-question examinations; one examination, the pretest, was taken before the students viewed the contents of the program, and the other examination, the posttest, was taken after completing the program. The mean score on the pretest was 61% (SD, 14%), the mean on the posttest was 91% (SD, 10%), and the improvement was significant. In addition, 4 questions about peripheral blood smears, which were based on printed images, were administered at the end of the hematology course. The students scored an average of 2.75 (SD, 0.86), and a positive correlation was found between these scores and the scores on the Tutor posttest. The results of the study suggest that PeripheralBlood-Tutor is feasible to implement, and it helps students learn to interpret peripheral blood smears. The use of PeripheralBlood-Tutor is now a requirement in the medical school curriculum, the medical technology program, and the pathology residency at the University of Washington, Seattle.

Taxonomic and functional implications of mandibular scaling in early hominins

Body mass estimates for fossil hominin taxa can be obtained from suitable postcranial and cranial variables. However, the nature of the taphonomic processes that winnow the mammalian fossil record are such that these data are usually only available for the minority of the specimens that comprise the hypodigm of a species. This study has investigated the link between species mean body mass and the height and width of the mandibular corpus in a core sample of 23 species of extant simians. The slopes of the least-squares regressions for the whole sample and for the hominoid subset are similar. However, the intercepts differ so that for a given body mass, a hominoid will generally have a smaller mandible than a generalized simian. The same mandibular measurements were taken on 75 early hominin mandibles assigned to eight species groups. When mandibular corpus height- and width-derived estimates of body mass for the fossil taxa were compared with available postcranial and cranial-derived body mass estimates, the eight early hominin species sort into four groups. The first, which includes A. afarensis and A. africanus, has mandibles which follow a "generalized simian" scaling relationship. The second group, which comprises the two "robust" australopithecine species, P. boisei and P. robustus, has mandibles which scale with body mass as if they are "super-simians," for they have substantially larger mandibles than a simian with the same body mass. The two "early Homo" species, H. habilis sensu stricto and H. rudolfensis, make up the third group. It has mandibular scaling relationships that are intermediate between that of the comparative simian sample and that of the hominoid subsample. The last of the four groups comprises H. ergaster and H. erectus; their mandibles scale with body mass as if they were hominoids, so that of the four groups they have the smallest mandibles per unit body mass. These results are related to comparable information about relative tooth size. Their relevance for attempts to interpret the dietary adaptations of early hominins are explored.

Infrared microspectroscopy and artificial neural networks in the diagnosis of cervical cancer

Infrared spectra of 88 normal and 32 abnormal (mild to severe dysplasia) cervical smear samples were used as a databank to investigate the usefulness of artificial neural networks (ANN) in the diagnosis of cervical smears. The spectra were first reduced, using principal component analysis (PCA), to seven wavenumber components that are the major contributors to the variance. A number of different ANN architectures were investigated that could differentiate between normal and abnormal cervical smears. Although the ANNs were trained to differentiate only normal from abnormal smears, the results using an independent test data set indicated that within the abnormal category mild dysplasia could be distinguished from severe dysplasia. The results using this restricted data set indicate that neural networks coupled to infrared microspectroscopy could provide an alternative automated means of screening for cervical cancer.

Pellagra in a woman using alternative remedies

A young woman presented with pellagra. Dietary intake of niacin was in excess of recommended guidelines. She had a low body mass index and was taking a number of alternative remedies. Resolution was rapid with oral nicotinic acid and discontinuation of the remedies.

Potent topical steroid in a Chinese herbal cream

Steroids have been discovered previously in oral "herbal" preparations. Using liquid chromatography, we have now confirmed the presence of the potent topical steroid, clobetasol proprionate, in a Chinese herbal cream.

The economic impact of high-risk pregnancies

To compare the costs of prenatal care, labor and delivery, and postnatal care of 775 high-risk (HR) pregnancies with costs of 2,825 low-risk pregnancies, data were collected from retrospective chart review and computerized financial records of infants and mothers. Claims paid to providers, hospitals, and ancillary services were the direct medical costs of care for Sentara Health Plan. The total prenatal, labor and delivery, and postnatal costs were more than 6 million dollars and 3.5 million dollars for premature and term babies, respectively. Postnatal and total costs were related inversely to gestational ages and birth weights and directly related to length of stay. The data indicate the substantially increased cost of identified HR pregnancies. The gestational age and birth weight correlate with postnatal and total costs.

Contact dermatitis from cetostearyl alcohol

Emulsifiers are an uncommon cause of allergic contact dermatitis. Five cases of allergic contact dermatitis to cetostearyl alcohol are presented. In all five cases, multiple positive reactions to other allergens were present, usually topical corticosteroid creams.

Nosocomial Trichophyton tonsurans in a long stay ward

AIMS

To document a nosocomial outbreak of Trichophyton tonsurans infection in a long stay ward.

METHOD

Retrospective review of mycology cultures taken from patients and staff during 1993-5 and clinical examination of both patients and staff.

RESULTS

Thirty-three mycology samples from 13 patients and staff, cultured T tonsurans during the period 1993-5. Twenty-two patients and staff were examined; 4 had mycology confirmed T tonsurans (2 scalp, 2 fingernail). Treatment with terbinafine 250 mg/day for 2 months resulted in clinical clearance (only 1 positive culture in 16 months follow-up).

SUMMARY

T tonsurans is emerging as an important pathogen which may cause nosocomial infections.

Herpes zoster brachial plexus neuritis

This is the first report of brachial plexus inflammation associated with clinical herpes zoster paresis. A 78-year-old female with a 3-week history of herpes zoster of the C4, C5, and C6 dermatomes developed left upper arm monoplegia. She died from an acute myocardial infarction. Post-mortem provided a rare opportunity to study the neuropathology of herpes zoster motor involvement. Histology of the brachial plexus showed extensive lymphocytic infiltration, myelin breakdown, and preservation of axons without vasculitis. The cervical spinal cord showed perivascular lymphocytic cuffing and no anterior horn necrosis. We suggest, the brachial plexus inflammation was a distal extension of a dorsal ganglionitis. Brachial plexus neuritis may be a direct cause of reversible upper limb paresis in herpes zoster. We demonstrate the motor neuropathy is an inflammatory demyelinative process consistent with the recovery observed in a number of patients. We postulate post-herpetic neuralgia may be related to an ongoing inflammatory process.

Human evolution

The common ancestor of modern humans and the great apes is estimated to have lived between 5 and 8 Myrs ago, but the earliest evidence in the human, or hominid, fossil record is Ardipithecus ramidus, from a 4.5 Myr Ethiopian site. This genus was succeeded by Australopithecus, within which four species are presently recognised. All combine a relatively primitive postcranial skeleton, a dentition with expanded chewing teeth and a small brain. The most primitive species in our own genus, Homo habilis and Homo rudolfensis, are little advanced over the australopithecines and with hindsight their inclusion in Homo may not be appropriate. The first species to share a substantial number of features with later Homo is Homo ergaster, or 'early African Homo erectus', which appears in the fossil record around 2.0 Myr. Outside Africa, fossil hominids appear as Homo erectus-like hominids, in mainland Asia and in Indonesia close to 2 Myr ago; the earliest good evidence of 'archaic Homo' in Europe is dated at between 600-700 Kyr before the present. Anatomically modern human, or Homo sapiens, fossils are seen first in the fossil record in Africa around 150 Kyr ago. Taken together with molecular evidence on the extent of DNA variation, this suggests that the transition from 'archaic' to 'modern' Homo may have taken place in Africa.

Multiple medicament allergies in two patients with chronic leg ulceration

Medicament allergies in patients with chronic leg ulcers is well recognized. In the past, topical antibiotics, rubber additives and wool alcohols have been the most common reported allergens. Allergy to topical corticosteroids has been reported. We document two cases of multiple corticosteroid allergy in patients with chronic leg ulceration.

Semistructured child sexual abuse interviews: interview and child characteristics related to credibility of disclosure

This study provided the first empirical description of child and interviewer behaviors occurring within semistructured assessment interviews with children suspected of being victims of sexual abuse. Specifically, relationships between child and interviewer characteristics and interview credibility were examined. Using the Child Abuse Interview Interaction Coding System (CAIICS, Wood, 1990), 55 videotaped interviews of high-risk sex abuse cases seen at a multidisciplinary assessment center were behaviorally coded. Support was found for the interrater reliability and criterion related validity of the CAIICS was found. Results also revealed that children were initially rated as relaxed and displayed few emotional behaviors. Thus, the assumption that a credible disclosure of abuse must necessarily include the display of emotion by the child was not supported. Second, several behavioral differences between preschool and school-aged children were identified: however, no meaningful gender differences were found. Third, supporting evidence was found for both age and gender effects in judgments of interview credibility, with girls and school-aged children judged as more credible. Fourth, while the interviewer did engage in so called leading behaviors, these behaviors were not found to be related to rating of interview credibility. However, interviewer behaviors may have affected interview credibility through an intervening variable. Finally, implications, for further use of the CAIICS for examining interviewer-child interactions, evaluating standards of practice, and assisting with interviewer training are discussed.

Hominid palaeobiology: have studies of comparative development come of age?

It is 70 years since Adolf Schultz urged his colleagues to consider how studies of primate growth and development could help them interpret the course of human evolution. This paper considers the evolutionary context of comparative growth studies. It compares and contrasts aspects of the ontogeny of living modern humans and chimpanzees, and considers whether relatively simple models of heterochronic change can account for the modifications which have taken place during the course of human evolutionary history.

Comparison of secondary structures in water of chondroitin-4-sulfate and dermatan sulfate: implications in the formation of tertiary structures

Chondroitin-4-sulfate (CS4) and dermatan sulfate (DS) were examined in D2O solution, with or without NaCl, by NMR at 300 MHz, to investigate the physicochemical consequences of epimerization of glucuronate (GlcUA in CS4) to iduronate (IdoUA in DS). Nuclear Overhauser effects (NOEs) and spin-lattice relaxation times following selective and nonselective inversion were measured at up to 70 degrees C. (1) NOEs confirmed 4C1 conformations of sugar rings in N-acetylgalactosamine and GlcUA, and 1C4 or 2S0 in IdoUA. Conflict between NMR data and periodate oxidation kinetics over IdoUA conformations is resolvable by postulating conversion of monodentate periodate-1C4 complexes to conformations in which periodate oxidation can procede. (2) Pairs of glycosidic protons in CS4 and DS showed strong NOEs, implying that stretches of 2-fold helix were present, with carboxylate and acetamido groups close to each other on the same side of tapelike molecules, extending previous work in dimethyl sulfoxide solution. CS4 and DS have large hydrophobic patches in this configuration, similar to those in keratan sulfate and hyaluronan. (3) Selective and nonselective inversion-recoveries implied similar segmental and backbone mobilities and hence flexibilities in CS4 and DS. This is discussed in terms of intrinsic flexibility of glycosidic conformations, modified by hydrogen-bonded arrays. (4) We postulate that hydrophobic and hydrogen bonding drives DS self-aggregation. Stronger self-aggregation of DS compared with CS4 is attributed to increased intermolecular hydrogen-bonding in DS, secondary to decreased intramolecular hydrogen-binding. This is partly because the axial OH groups in 1C4 IdoUA cannot hydrogen-bond to neighboring sugars as can the equatorial OH groups in GlcUA of CS4.