Granulomatous disease associated with Bartonella infection in 2 dogs

Shortly after removal of an engorged tick from the left ear, a 4-year-old Greyhound was referred for evaluation of fever and a rapidly enlarging mass in the region of the left submandibular lymph node. Histopathologic evaluation of the lymph node resulted in a diagnosis of severe granulomatous lymphadenitis. An 11-year-old mixed-breed dog was referred for evaluation of a 6-week history of serous nasal discharge. Histologic examination of a surgical biopsy from a nasal mass indicated multifocal granulomatous inflammation with fibrosis. Serum samples obtained from both dogs were reactive by immunofluorescent assay to Bartonella vinsonii subsp. berkhoffii antigens (reciprocal titers of 128). Although Bartonella organisms were not isolated by lysis centrifugation blood culture, Bartonella DNA was amplified from tissue samples obtained from each dog (lymph node biopsy from dog 1 and nasal biopsy from dog 2) using primers that amplify a portion of the 16S rRNA gene followed by Southern blot hybridization using a genus-specific probe. Additionally, restriction fragment length polymorphism (RFLP) analysis of a Bartonella-specific citrate synthase gene product obtained from dog 2 resulted in a restriction pattern identical to B. vinsonii subsp. berkhoffii. This is the 1st report of granulomatous disease in dogs associated with Bartonella infection.

Diabetes care: a comparison of management systems

During 1997, the Alaska Area Diabetes Program audited a sample of 837 charts from among the 1373 individuals receiving regular diabetes care at facilities serving predominantly American Indians/Alaska Natives. Charts were evaluated for the delivery of American Diabetes Association Standards of Care. Results of the audit showed a great deal of variability among facilities. Facilities which scored highly in the audit were more likely to use an organized multidisciplinary team approach that included coordinated clinic appointments with multiple providers on the same day, maintenance of a diabetes registry, proactive preclinic preparation, flow-sheet use, intensive individual nutritional counseling, a case manager or field clinic coordinator system with standing orders, and strong self-management support.

Estradiol/progesterone substitution in the luteal phase improves pregnancy rates in stimulated cycles--but only in younger women

Innumerable studies have attempted to demonstrate that hormonal support of the luteal phase during ovulation induction cycles improves pregnancy rates. None has, however, so far been able to confirm the validity of such treatment conclusively, possibly because most studies only utilized progesterone substitution. Since luteal phase endometrium also requires estradiol support, this study attempted to investigate whether hormone substitution with progesterone and estradiol would be more successful in improving pregnancy rates. Amongst approximately 7500 consecutive ovulation induction cycles were identified prospectively which were characterized by a precipitous drop of luteal phase serum estradiol levels by more than 50% over a 48 hour period within 10 days from hCG administration. Those cycles were prospectively randomized to oral micronized estradiol substitution (Group I) or not (Group II), while both groups received routine progesterone substitution of the luteal phase. Cycles were then evaluated in regards to the occurrence of chemical, ectopic and clinical pregnancies. One hundred sixty-three Group I cycles resulted in 34 pregnancies (20.9%), which compared favorably to 21 pregnancies in 167 Group II patients (12.6%) (x2[1] = 4.06; p < 0.04). The advantage for Group I cycles (29/95 pregnancies, 31%) vs. Group II cycles (16/105, 15%) became even more pronounced when only women up to age 35 years were evaluated. Estradiol substitution maintained a significant advantage until age 38 (x2 [1] = 6.87; p < 0.009). While gravidity did not affect pregnancy success, estradiol substitution in Group I benefited nulliparous (23% pregnancy rate) over multiparous women (12% pregnancy rate) (x2 [2] = 6.86; p< 0.03). This association was, however, age-dependent. A combined estradiol and progesterone substitution of the luteal phase of ovulation induction cycles increases the overall pregnancy rate. Since estradiol substitution was initiated in this study only once a precipitous drop in serum estradiol levels had already taken place, an even larger improvement in pregnancy rates could conceivably be possible if earlier estradiol substitution of the luteal phase is initiated. A further expansion of investigations of similar protocols for routine ovulation induction and in vitro fertilization (IVF) cycles may be indicated, especially in women below age 38 years and in nulliparous females.

Country-specific estimates and models of HIV and AIDS: methods and limitations

OBJECTIVE

This paper presents the methods used to calculate the end of 1997 country-specific estimates of HIV and AIDS produced by the UNAIDS/WHO Working Group on Global HIV/AIDS and STD Surveillance. The objective of this exercise was to improve estimates on HIV/AIDS by using country-specific models of HIV/AIDS epidemics. The paper describes and discusses the processes and obstacles that were encountered in this multi-partner collaboration including national and international experts.

METHODS

The 1997 estimates required two basic steps. First, point prevalence estimates for 1994 and 1997 were carried out and the starting year of the epidemic was determined for each country. The procedures used to calculate the estimates of prevalence differed according to the assumed type of the epidemic and the available data. The second step involved using these estimates of prevalence over time and the starting date of the epidemic to determine the epidemic curve that best described the spread of HIV in each particular country. A simple epidemiological program (EPIMODEL) was used for the calculation of estimates on incidence and mortality from this epidemic curve.

RESULTS

Regional models that were used in previous estimation exercises were not able to capture the diversity of HIV epidemics between countries and regions. The result of this first country-specific estimation process yielded higher estimates of HIV infection than previously thought likely, with over 30 million people estimated to be living with HIV/AIDS. The application of survival times that are specific to countries and regions also resulted in higher estimates of mortality, which more accurately describe the impact of the epidemics. At the end of 1997, it was estimated that 11.7 million people worldwide had died as a result of HIV/AIDS since the beginning of the epidemic.

CONCLUSION

This exercise is an important step in improving understanding of the spread of HIV in different parts of the world. There are, however, shortcomings in the current systems of monitoring the epidemic. Improvements in HIV surveillance systems are needed in many parts of the world. In addition, further research is needed to understand fully the effects of the fertility reduction as a result of HIV, differing sex ratios in HIV infection and other factors influencing the course and measurement of the epidemic.

Crystal structure of a thwarted mismatch glycosylase DNA repair complex

The bacterial mismatch-specific uracil-DNA glycosylase (MUG) and eukaryotic thymine-DNA glycosylase (TDG) enzymes form a homologous family of DNA glycosylases that initiate base-excision repair of G:U/T mismatches. Despite low sequence homology, the MUG/TDG enzymes are structurally related to the uracil-DNA glycosylase enzymes, but have a very different mechanism for substrate recognition. We have now determined the crystal structure of the Escherichia coli MUG enzyme complexed with an oligonucleotide containing a non-hydrolysable deoxyuridine analogue mismatched with guanine, providing the first structure of an intact substrate-nucleotide productively bound to a hydrolytic DNA glycosylase. The structure of this complex explains the preference for G:U over G:T mispairs, and reveals an essentially non-specific pyrimidine-binding pocket that allows MUG/TDG enzymes to excise the alkylated base, 3, N(4)-ethenocytosine. Together with structures for the free enzyme and for an abasic-DNA product complex, the MUG-substrate analogue complex reveals the conformational changes accompanying the catalytic cycle of substrate binding, base excision and product release.

Comparative pathology and pathogenesis of spontaneous and experimentally induced fibropapillomas of green turtles (Chelonia mydas)

Tumor biopsy samples from 25 Floridian and 15 Hawaiian green turtles (Chelonia mydas) with spontaneous green turtle fibropapillomatosis (GTFP) and from 27 captive-reared green turtles with experimentally induced GTFP were examined microscopically to differentiate the histologic features that result from GTFP pathogenesis and those that result from incidental factors that may vary according to geographic region. Common histologic features for spontaneous and experimentally induced tumors included fibroblast proliferation in the superficial dermis, epidermal acanthosis and hyperkeratosis, epidermal basal cell degeneration with dermal-epidermal cleft formation, spinous layer degeneration with intraepidermal vesicle and pustule formation, and ulceration. Visceral tumors, found in eight of 10 (80%) free-ranging turtles with cutaneous disease that were examined after death, had extensive interstitial fibrous proliferation. The presence of spirorchid trematode eggs and associated foreign body granulomas, common secondary findings within spontaneous tumors, varied by geographic location, and these findings were not observed in experimentally induced tumors. Eosinophilic intranuclear inclusions and intranuclear herpesvirus-associated antigen immunoreactivity were found in 18 of 38 (47%) experimentally induced cutaneous tumors and nine of 119 (7.5%) spontaneous tumors from Floridian but not Hawaiian turtles. The possible involvement of GTFP-associated herpesvirus in the pathogenesis of epidermal degenerative changes and GTFP pathogenesis is discussed.

Implementation of a case coordinator role: a focused ethnographic study

This study was a focused ethnography of a 21-bed, inpatient psychiatric unit. Patient care was provided by a multidisciplinary team, and a case coordinator role was developed to coordinate the team's efforts. The purpose of the study was to describe perceptions of the implementation of the case coordinator role. Data collection methods included document review, participant and nonparticipant observation, and personal interviews of key informants. Field notes and transcriptions were analyzed throughout data collection. Three themes were identified: role development, role confusion, and role expectation. Role development was defined as the process of recognizing the need for and instituting the position of case coordinator. Role confusion was defined as the lack of a clear distinction between the role of the case coordinator and the role of the staff nurse. Role expectation was defined as the process of directing the development of the role based on individuals' perceptions of the role. Although the role as implemented had not met initial expectations, team members were confident the role would evolve to fulfill the unit's needs.

DNA triple helix stabilisation by covalent attachment of a triplex-specific ligand

We have prepared oligonucleotides with a naphthylquinoline triplex-binding ligand covalently tethered to the 5'-end and have used UV-melting and DNase I footprinting to examine the stability of intra- and inter-molecular triplexes containing this modification. We find that covalent attachment of the ligand increases the melting temperature of intramolecular 6-mer triplexes by about 14 K, and increases the binding of 9-mer oligonucleotides to their duplex target sites by about 60-fold.

DNA triple helix formation at target sites containing several pyrimidine interruptions: stabilization by protonated cytosine or 5-(1-propargylamino)dU

DNase I footprinting has been used to study the formation of parallel triplexes at oligopurine target sequences which are interrupted by pyrimidines at regular intervals. TA interruptions are targeted with third strand oligonucleotides containing guanine, generating G x TA triplets, while CG base pairs are targeted with thymine, forming T x CG triplets. We have attempted to optimize the stability of these complexes by varying the base composition and sequence arrangement of the target sites, and by replacing the third strand thymines with the positively charged analogue 5-(1-propargylamino)dU (U(P)). For the target sequence (AAAT)(5)AA, in which pyrimidines are positioned at every fourth residue, triplex formation with TG-containing oligonucleotides is only detected in the presence of a triplex-binding ligand, though stable triplexes were detected at the target site (AAAAAT)(3)AAAA. Triplex stability at targets containing pyrimidines at every fourth residue is increased by introducing guanines into the duplex repeat unit using the targets (AGAT)(5)AA and (ATGA)(5)AA. In contrast, placing C(+) x GC triplets on the 5'-side of G x TA, using the target (AGTA)(5)TT, produces complexes of lower stability. We have attempted further to increase the stability of these complexes by using the positively charged thymine base analogue U(P), and have shown that (TU(P)TG)(5)TT forms a more stable complex with target (AAAT)(5)AA than the unmodified third strand, generating a footprint in the absence of a triplex-binding ligand. Triplex formation at (AGTA)(5)AA is improved by using the modified oligonucleotide (TCGU(P))(5)TT, generating a complex in which the charged triplets C(+) x GC and U(P) x AT alternate with uncharged triplets. In contrast, placing U(P) x AT triplets adjacent to C(+) x GC, using the third strand oligonucleotide (U(P)CGT)(5)TT, reduces triplex formation, while the third strand with both substitutions, (U(P)CGU(P))(5)TT, produces a complex with intermediate stability. It appears that, although adjacent U(P) x AT triplets form stable triplexes, placing U(P) x AT adjacent to C(+) x GC is unfavorable. Similar results were obtained with fragments containing CG inversions within the oligopurine tract, though triplexes at (AAAAAC)(3)AA were only detected in the presence of a triplex-binding ligand. Placing C(+) x GC on the 5'-side of T x CG triplets also reduces triplex formation, while a 3'-C(+) x GC produces complexes with increased stability.

Gap junctions regulate responses of tendon cells ex vivo to mechanical loading

Avian digital flexor tendons were used with a device to apply load ex vivo to study the effects on deoxyribonucleic acid and collagen synthesis when cell to cell communication is blocked. Flexor digitorum profundus tendons from the middle toe of 52-day-old White Leghorn chickens were excised and used as nonloaded controls, or clamped in the jaws of a displacement controlled tissue loading device and mechanically loaded for 3 days at a nominal 0.65% elongation at 1 Hz for 8 hours per day with 16 hours rest. Tendon samples were radiolabeled during the last 16 hours with 3H-thymidine to monitor deoxyribonucleic acid synthesis or with 3H-proline to radiolabel newly synthesized collagen. Cyclic loading of whole avian flexor tendons stimulated deoxyribonucleic acid and collagen synthesis, which could be blocked with octanol, a reversible gap junction blocker. Cells from human digital flexor tendon were used to populate a rectangular, three-dimensional, porous, polyester foam that could be deformed cyclically in vitro. Together, these results support the hypothesis that tendon cells must communicate to sustain growth and matrix expression and that an engineered three-dimensional construct can be used to study responses to mechanical load in vitro.

Outcome after surgical repair of junctional epidermolysis bullosa-pyloric atresia syndrome: a report of 3 cases and review of the literature

BACKGROUND

Junctional epidermolysis bullosa-pyloric atresia syndrome is recognized as a distinct autosomal recessive entity. Affected infants present with skin fragility and inability to feed due to intestinal obstruction. Despite successful surgical repair of the anatomical defect, the outcome is poor owing to poor feeding, malabsorption, failure to thrive, and sepsis.

OBSERVATIONS

In 70 cases of intestinal obstruction and epidermolysis bullosa reported in the medical literature and the 3 reported here, surgical intervention was attempted 51 times. In all except 16 infants, death occurred before age 11 months (mean age, 70 days). Renal involvement and continued failure to thrive accompanied the skin disease in survivors, who ranged in age from 30 days to 16 years (mean age, 4.0 years).

CONCLUSIONS

The poor prognosis of this condition must be considered when decisions are made regarding surgical correction. Attempting surgical correction may be warranted in individual circumstances, but withholding surgical intervention and providing palliative support is an acceptable alternative.

Severe delayed hemolytic transfusion reaction secondary to anti-At(a)

BACKGROUND

Anti-At(a) is a rare red cell (RBC) alloantibody found in the black population. It has been described as causing one case of mild hemolytic disease of the newborn, but its ability to cause hemolytic transfusion reactions is uncertain.

CASE REPORT

The patient was a 60-year-old black female with a history of three uneventful pregnancies but no transfusions. On admission, her direct and indirect antiglobulin tests were negative, total bilirubin was 0.5 mg per dL, and lactate dehydrogenase was 224 IU per L. She received nine units of compatible RBCs in the perioperative period of a hemicolectomy. Her hemoglobin rose appropriately and stabilized at 12.6 g per dL by the 6th postoperative day. By Day 10 after surgery her hemoglobin had dropped to 6.8 g per dL, and her total bilirubin and lactate dehydrogenase had risen to 1.4 mg per dL and 783 IU per L, respectively. The direct and indirect antiglobulin tests were now newly positive with strengths of 3+. A warm hemolytic autoantibody was suspected. She was transfused two units of incompatible RBCs for a rapidly falling hemoglobin and symptomatic anemia. On Day 11, the total bilirubin rose to 3.5 mg per dL, and the lactate dehydrogenase was 1154 IU per L with a hemoglobin of 7.6 g per dL. Corticosteroids were begun. Studies of serum and an acid eluate revealed anti-At(a), but no other RBC antibodies. The patient stabilized, and further transfusion was avoided.

CONCLUSION

Although anti-At(a) was previously described as being of uncertain clinical significance, this patient demonstrated the ability of the antibody to cause a severe delayed hemolytic transfusion reaction.

The keratinocyte-derived cytokine IL-7 increases adhesion of the epidermal T cell subset to the skin basement membrane protein laminin-5

Human epidermis contains a subset of epidermal T cells that can mount an immune response by migrating through the skin and into the peripheral lymphnodes to proliferate before re-entering the epidermis. The cytokine IL-7 is shown to be localized to the basement membrane of normal human skin. Furthermore, culturing in the presence of IL-7 causes increased adhesion of epidermal T cells but not peripheral blood T cells to the major epidermal basement membrane protein, laminin-5. The mechanism for increased T cell adhesion to laminin-5 is due, at least in part, to an increase in the cell surface expression of the integrin alpha3beta1. Epidermal T cells cultured in IL-7 that are strongly adherent to laminin-5 are shown by flow cytometry to consist of a variety of subsets; therefore, the increase in cell adhesion is not due to an outgrowth of one T cell subset during culturing. We hypothesize that in vivo, exposure to IL-7 is required for epidermal T cell adhesion to laminin-5.

Species, interindividual, and tissue specificity in endocrine signaling

The activity of endocrine-active agents exhibits specificity at many levels. Differential responsiveness to these agents has been observed between different species and extends to interindividual differences within a species and between different tissues as well. In cases where they have been identified, the biologic and molecular mechanisms underlying this specificity are quite diverse. Determinants of species specificity include differences that exist in receptor binding, gene transcription, and cellular responses to endocrine-active compounds between species. Interindividual differences in responsiveness may be determined at the level of genetic polymorphisms in hormone-metabolizing enzymes, hormone receptors, and in those genes that are transactivated by these receptors, as well as during changing windows of susceptibility that occur as a function of age, such as prenatal and postmenopausal exposures. Extrinsic factors such as diet can also impact individual susceptibility to endocrine-active agents. Tissue-specific determinants of susceptibility are well documented, but little is known regarding the mechanisms underlying these different responses. Differences in the expression of accessory proteins for steroid hormone receptors and different patterns of receptor expression, estrogen receptor alpha and estrogen receptor beta; for example, may contribute to tissue specificity, as may differences in the pattern of expression of other genes such as hormone-metabolizing enzymes. The use of animal model systems and development of appropriate mathematical models has the potential to yield additional valuable information for elucidating the role of these determinants of specificity at low-dose exposures and for improved risk assessments for the adverse health effects of endocrine-active compounds.

Detection of PCR products using self-probing amplicons and fluorescence

Molecular diagnostics is progressing from low-throughput, heterogeneous, mostly manual technologies to higher throughput, closed-tube, and automated methods. Fluorescence is the favored signaling technology for such assays, and a number of techniques rely on energy transfer between a fluorophore and a proximal quencher molecule. In these methods, dual-labeled probes hybridize to an amplicon and changes in the quenching of the fluorophore are detected. We describe a new technology that is simple to use, gives highly specific information, and avoids the major difficulties of the alternative methods. It uses a primer with an integral tail that is used to probe an extension product of the primer. The probing of a target sequence is thereby converted into a unimolecular event, which has substantial benefits in terms of kinetics, thermodynamics, assay design, and probe reliability.

Preliminary assessment of extrastriatal dopamine D-2 receptor binding in the rodent and nonhuman primate brains using the high affinity radioligand, 18F-fallypride

We have identified the value of 18F-fallypride [(S)-N-[(1-allyl-2-pyrrolidinyl)methyl]-5-(3-[18F]fluoropropyl)-2, 3-dimethoxybenzamide], as a dopamine D-2 receptor radiotracer for the study of striatal and extrastriatal receptors. Fallypride exhibits high affinities for D-2 and D-3 subtypes and low affinity for D-4 (3H-spiperone IC50s: D-2 = 0.05 nM [rat striata], D-3 = 0.30 nM [SF9 cell lines, rat recombinant], and D-4 = 240 nM [CHO cell lines, human recombinant]). Biodistribution in the rat brain showed localization of 18F-fallypride in striata and extrastriatal regions such as the frontal cortex, parietal cortex, amygdala, hippocampus, thalamus, and hypothalamus. In vitro autoradiographic studies in sagittal slices of the rat brain showed localization of 18F-fallypride in striatal and several extrastriatal regions, including the medulla. Positron emission tomography (PET) experiments with 18F-fallypride in male rhesus monkeys were carried out in a PET VI scanner. In several PET experiments, apart from the specific binding seen in the striatum, specific binding of 18F-fallypride was also identified in extracellular regions (in a lower brain slice, possibly the thalamus). Specific binding in the extrastriata was, however, significantly lower compared with that observed in the striata of the monkeys (extrastriata/cerebellum = 2, striata/cerebellum = 10). Postmortem analysis of the monkey brain revealed significant 18F-fallypride binding in the striata, whereas binding was also observed in extrastriatal regions such as the thalamus, cortical areas, and brain stem.

Anti-G in a pregnant patient

BACKGROUND

Anti-G is a red cell (RBC) antibody of the Rh system. It has been described in pregnant women only in association with anti-D or anti-C; therefore, the ability of this antibody alone to cause hemolytic disease of the newborn is uncertain. One case in which this antibody caused no clinical sequelae is reported.

CASE REPORT

The patient was a 35-year-old primigravida with type O, D-, C-, E-, c+ RBCs who was given 4 units of type O, D- allogeneic RBCs and 2 units of autologous RBCs 2 years antepartum. She was found to have anti-D and anti-C by an outside laboratory as part of a routine prenatal work-up. Further evaluation by our laboratory revealed the presence of anti-G and possible anti-C without anti-D. Titers at 22 weeks' gestation were 64 against r'r RBCs and 16 against R2R2 RBCs; these remained unchanged throughout the pregnancy. Amniocentesis performed at Weeks 28 and 32 showed no evidence of hemolytic disease of the newborn. A healthy 3.3-kg infant was delivered at 36 weeks' gestation. Prophylactic Rh immune globulin was administered antepartum and postpartum. The infant's RBCs were type O, D+, c+ C-, E-, and the direct antiglobulin test was positive. An acid eluate prepared from the baby's RBCs revealed anti-G. The total bilirubin was 5.5 mg per dL at birth, and the hematocrit was 66 percent. Total bilirubin peaked on Day 5 at 11.9 mg per dL, and no therapeutic intervention was required.

CONCLUSIONS

Anti-G alone caused little if any fetal or neonatal hemolysis in this case. Although further study is needed, invasive fetal monitoring may be unnecessary if anti-G is the sole cause of fetomaternal RBC incompatibility.

A role for maternal serum screening in detecting chromosomal abnormalities in fetuses with isolated choroid plexus cysts: a prospective multicentre study

A prospective multicentre study was performed to identify patients with fetal choroid plexus cysts and examine the association between choroid plexus cysts and chromosome abnormalities in the context of variables such as maternal age, serum triple-screen results, race, other prenatally-identified fetal anomalies and cyst characteristics. A total of 18 437 scans were performed in 5 centres and 257 fetuses were identified with choroid plexus cysts. Outcome was available on 250 patients, and of these, chromosomal abnormalities were detected in a total of 13 (5.2 per cent) fetuses. 26 patients in the group had additional ultrasound abnormalities, and 8 of these had fetal chromosome abnormalities. Among the 224 patients with isolated choroid plexus cysts, 5 (2.2 per cent) were found to have chromosomal abnormalities. All cases with identified chromosomal abnormalities were associated with an additional risk factor, such as other ultrasound findings, advanced maternal age or abnormal maternal serum triple-screen results.

5-(1-propargylamino)-2'-deoxyuridine (UP): a novel thymidine analogue for generating DNA triplexes with increased stability

We have used quantitative DNase I footprinting and UV-melting studies to examine the formation of DNA triplexes in which the third strand thymines have been replaced by 5-propargylamino-dU (UP). The intra-molecular triplex A6-L-T6-L-(UP)5T (L = two octanediol residues) shows a single UV-melting transition which is >20 degrees higher than that of the parent triplex A6-L-T6-L-T6at pH 5.5. Although a single transition is observed at all pHs, the melting temperature (Tm) of the modified oligonucleotide decreases at higher pHs, consistent with the requirement for protonation of the amino group. A similar intramolecular triplex with a longer overhanging duplex shows two melting transitions, the lower of which is stabilised by substitution of T by UP, in a pH dependent fashion. Triplex stability increases by approximately 12 K for each T to UP substitution. Quantitative footprinting studies have examined the interaction of three UP-containing 9mer oligonucleotides with the different portions of the 17mer sequence 5'-AGGAAGAGAAAAAAGAA. At pH 5.0, the UP-containing oligo-nucleotides footprint to much lower concentrations than their T-containing counterparts. In particular (UP)6CUPT binds approximately 1000-fold more tightly than the unmodified oligonucleotide T6CTT. Oligonucleotides containing fewer UP residues are stabilised to a lesser extent. The affinity of these modified third strands decreases at higher pHs. These results demonstrate that the stability of DNA triplexes can be dramatically increased by using positively charged analogues of thymine.

Comparison of cervicovertebral dimensions in Australian Aborigines and Caucasians

Cervicovertebral dimensions were compared in a group of 30 male and 30 female young adult Australian Aborigines from the Northern Territory, and a control sample consisting of 60 Caucasian dental students from Adelaide, matched for sex and age. Thirty-six variables, 22 cervical and 14 craniofacial, were derived from standardized lateral roentgenograms with the use of a computerized cephalometric system. Vertebral body height and length were significantly greater in Aboriginal males than females for C3 to C7, while dorsal arch height of C1 and C2 displayed the greatest dimensional variability in both sexes. The antero-posterior length of C1, dens height, and body heights of C3 and C4 were significantly shorter in Aborigines than Caucasians for both males and females. Total length of the column from C2 to C6 was approximately 12 per cent shorter in the Aborigines compared with Caucasians. The height of the posterior arch of C1 was significantly correlated with one or both posterior cranial base lengths in Aborigines and Caucasians. Associations were also noted between mandibular lengths and posterior arch heights of the upper two vertebrae. The results confirm and clarify several previous observations on the relative shortness of the cervical spine in Australian Aboriginals. They also indicate some associations between dimensions of the cervical vertebrae and craniofacial lengths, particularly those representing the posterior cranial base and the mandible.