Pulmonary anatomy and a case of unilateral aplasia in a common snapping turtle (Chelydra serpentina): developmental perspectives on cryptodiran lungs.

The common snapping turtle (Chelydra serpentina) is a well studied and broadly distributed member of Testudines; however, very little is known concerning developmental anomalies and soft tissue pathologies of turtles and other reptiles. Here, we present an unusual case of unilateral pulmonary aplasia, asymmetrical carapacial kyphosis, and mild scoliosis in a live adult C. serpentina. The detailed three-dimensional (3D) anatomy of the respiratory system in both the pathological and normal adult C. serpentina, and a hatchling are visualized using computed tomography (CT), microCT, and 3D digital anatomical models. In the pathological turtle, the right lung consists of an extrapulmonary bronchus that terminates in a blind stump with no lung present. The left lung is hyperinflated relative to the normal adult, occupying the extra coelomic space facilitated by the unusual mid-carapacial kyphotic bulge. The bronchial tree of the left lung retains the overall bauplan of the normal specimens, with some minor downstream variation in the number of secondary airways. The primary difference between the internal pulmonary structure of the pathological individual and that of a normal adult is a marked increase in the surface area and density of the parenchymal tissue originating from the secondary airways, a 14.3% increase in the surface area to volume ratio. Despite this, the aplasia has not had an impact upon the ability of the turtle to survive; however, it did interfere with aquatic locomotion and buoyancy control under water. This turtle represents a striking example of a non-fatal congenital defect and compensatory visceral hypertrophy.

Computed tomography arthrography with traction in the human hip for three-dimensional reconstruction of cartilage and the acetabular labrum.

AIM: To develop and demonstrate the efficacy of a computed tomography arthrography (CTA) protocol for the hip that enables accurate three-dimensional reconstructions of cartilage and excellent visualization of the acetabular labrum. MATERIALS AND METHODS: Ninety-three subjects were imaged (104 scans); 68 subjects with abnormal anatomy, 11 patients after periacetabular osteotomy surgery, and 25 subjects with normal anatomy. Fifteen to 25 ml of contrast agent diluted with lidocaine was injected using a lateral oblique approach. A Hare traction splint applied traction during CT. The association between traction force and intra-articular joint space was assessed qualitatively under fluoroscopy. Cartilage geometry was reconstructed from the CTA images for 30 subjects; the maximum joint space under traction was measured. RESULTS: Using the Hare traction splint, the intra-articular space and boundaries of cartilage could be clearly delineated throughout the joint; the acetabular labrum was also visible. Dysplastic hips required less traction (∼5 kg) than normal and retroverted hips required (>10 kg) to separate the cartilage. An increase in traction force produced a corresponding widening of the intra-articular joint space. Under traction, the maximum width of the intra-articular joint space during CT ranged from 0.98-6.7 mm (2.46 ± 1.16 mm). CONCLUSIONS: When applied to subjects with normal and abnormal hip anatomy, the CTA protocol presented yields clear delineation of the cartilage and the acetabular labrum. Use of a Hare traction splint provides a simple, cost-effective method to widen the intra-articular joint space during CT, and provides flexibility to vary the traction as required.

Localizing the L5 Vertebra Using Nerve Morphology on MRI: An Accurate and Reliable Technique.

BACKGROUND AND PURPOSE: Multiple methods have been used to determine the lumbar vertebral level on MR imaging, particularly when full spine imaging is unavailable. Because postmortem studies show 95% accuracy of numbering the lumbar vertebral bodies by counting the lumbar nerve roots, attention to lumbar nerve morphology on axial MR imaging can provide numbering clues. We sought to determine whether the L5 vertebra could be accurately localized by using nerve morphology on MR imaging. MATERIALS AND METHODS: One hundred eight cases with full spine MR imaging were numbered from the C2 vertebral body to the sacrum with note of thoracolumbar and lumbosacral transitional states. The origin level of the L5 nerve and iliolumbar ligament were documented in all cases. The reference standard of numbering by full spine imaging was compared with the nerve morphology numbering method. Five blinded raters evaluated all lumbar MRIs with nerve morphology technique twice. Prevalence and bias-adjusted κ were used to measure interrater and intrarater reliability. RESULTS: The L5 nerve arose from the 24th presacral vertebra (L5) in 106/108 cases. The percentage of perfect agreement with the reference standard was 98.1% (95% CI, 93.5%-99.8%), which was preserved in transitional and numeric variation states. The iliolumbar ligament localization method showed 83.3% (95% CI, 74.9%-89.8%) perfect agreement with the reference standard. Inter- and intrarater reliability when using the nerve morphology method was strong. CONCLUSIONS: The exiting L5 nerve can allow accurate localization of the corresponding vertebrae, which is essential for preprocedure planning in cases where full spine imaging is not available. This neuroanatomic method displays higher agreement with the reference standard compared with previously described methods, with strong inter- and intrarater reliability.

Validation for use with coyotes (Canis latrans) of a commercially available enzyme-linked immunosorbent assay for Dirofilaria immitis.

Serological tests offer a potentially powerful tool for monitoring parasites in wildlife populations. However, such tests must be validated before using them with target wildlife populations. We evaluated in coyotes (Canis latrans) the performance of a commercially available serological test used to detect canine heartworm (Dirofilaria immitis) in domestic dogs. We obtained 265 coyote carcasses and serological specimens from 54 additional coyotes from several regions of California, USA. We necropsied coyotes to determine the adult heartworm infection status. Blood was collected at necropsy on filter paper strips and allowed to dry; it was later eluted in a buffer solution, and the supernatant was tested for heartworm. Receiver operating characteristic (ROC) analysis was used to assess discriminatory power of the test and indicated a 93% probability that a randomly selected infected coyote would exhibit a higher enzyme-linked immunosorbent assay (ELISA) value than a randomly selected uninfected coyote. We estimated specificity at 96% (95% CI: 92-98%) for 165 uninfected coyotes and sensitivity at 85% (77-91%) for 100 infected coyotes, results similar to published values for the commercial serological test used with dog serum or plasma. Test performance was similar for filter paper specimens and supernatant of frozen whole blood collected in EDTA tubes (i.e. hemolyzed plasma). We found no difference in test performance among geographic or demographic coyote groups. Our findings support application of the test to filter paper or standard serological specimens for detection of heartworm in coyote populations.

Osteochondral injuries.

Osteochondral injuries are an important type of musculoskeletal trauma that can lead to disabling arthritis if not recognized and treated appropriately in the early stages. The anatomic configuration and biomechanical function of a joint are important for understanding its particular pattern of osteochondral injury and the resultant imaging appearance. The imaging of osteochondral fractures and osteochondrosis dissecans (OCD) is reviewed in this article, with particular attention to differentiating surgical and nonsurgical lesions on the basis of their appearance with advanced imaging modalities. Computed tomography (CT) and magnetic resonance imaging (MRI) have improved both the sensitivity and specificity for detection and characterization of osteochondral injuries. MRI is currently the modality of choice for the detection and staging of osteochondral injuries. It has the greatest sensitivity owing to its ability to depict marrow edema and directly assess the fracture clefts of stage 3 lesions, as well as the morphology of articular cartilage. Newer strategies for differentiating stable from unstable osteochondral fragments include MR arthrography and intravenous contrast-enhanced MRI.

The management of tetanus 1996.

The three main basic concepts in the understanding and management of tetanus: (1) Tetanus is polysystemic in terms of pathology and management. Most body organs, as well as the nervous system, are severely affected by tetanus toxins. (2) Prevention is not only by immunization, but also by specific treatment. Since the toxin cannot be therapeutically eradicated from the body, therapy is directed towards preventing continued spread of the toxins and the consequences of intoxication. (3) Variability in terms of prevalence and prognosis. The natural incidence and severity of tetanus varies greatly with social environment, season, climate and soil. Prognosis is influenced by age, source of infection and delay in treatment.

A new distal arthrogryposis syndrome characterized by plantar flexion contractures.

The distal arthrogryposis (DA) syndromes are a distinct group of disorders characterized by contractures of two or more different body areas. More than a decade ago, we revised the classification of DAs and distinguished several new syndromes. This revision has facilitated the identification of five genes (i.e., TNNI2, TNNT3, MYH3, MYH8, and TPM2) that encode components of the contractile apparatus of fast-twitch myofibers and cause DA syndromes. We now report on the phenotypic features of a novel DA disorder characterized primarily by plantar flexion contractures in a large five-generation Utah family. Contractures of hips, elbows, wrists, and fingers were much milder though they varied in severity among affected individuals. All affected individuals had normal neurological examinations; electromyography and creatinine kinase levels were normal on selected individuals. We have tentatively labeled this condition distal arthrogryposis type 10 (DA10).

Contraceptive information and promiscuity.

PIP: The author disputes the opinion that contraceptive information and sexual education in the schools does not contribute to promiscuity. Citing the increase in venereal disease cases treated in clinics (from 80,000 in 1949 to 282,000 in 1973), increased illegitimate births to women under age 20, and a 90% increase in abortions among girls 18 and under, he suggests that contraceptive discussions in the schools leave the implication that children are supposed to be sexually active. It appears the most reliable method of contraception misses the attention of many who give sex education. This method is simply - ''no.''^ieng

Intrathecal antitetanus serum (horse) in the treatment of tetanus.

In a two-year study of 322 conservatively treated, consecutive cases of tetanus in a rural hospital (all over twelve months old), intrathecal administration of 200 units of antitetanus serum (A.T.S.) (horse) reduced the overall mortality of 4-5% (5/110) compared with 14-5% (16/111) in the control series. 200 units intrathecal A.T.S. (horse) gave better results than 1500 units A.T.S. (horse). The results with lumbar and cisternal administration did not differ. It is suggested that tetanus is a polysystemic condition requiring polysystemic therapy. A regimen in which intrathecal A.T.S. is given as an adjunct to low-dosage systemic A.T.S., high levels of systemic betamethasone and diazepam, and careful nursing gave results which compare favourably with those of centres with more elaborate equipment and specialised staff.