Coralline hydroxyapatite bone graft substitutes: preliminary report of radiographic evaluation

A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties.     

Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability

In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction.     

Effectiveness of methyl-GAG (methylglyoxal-bis[guanylhydrazone]) in patients with advanced malignant lymphoma

We treated 51 patients with advanced malignant lymphoma refractory to conventional therapy with methyl-glyoxal-bis(guanylhydrazone) (methyl- GAG) at doses ranging from 400 to 800 mg/sq m. Therapy was started on a weekly schedule and was switched to every other week in responding patients at the onset of toxicity. Partial responses were observed in 6 of 13 evaluable patients with Hodgkin's disease (46%), 5 of 10 patients with diffuse poorly differentiated lymphocytic lymphoma (50%), 2 of 4 patients with nodular poorly differentiated lymphocytic lymphoma (50%), and 3 of 13 patients with diffuse histiocytic lymphoma (23%). Two of six patients with mycosis fungoides showed objective improvement in cutaneous disease. Toxicity was generally mild and included muscular weakness, myalgia, mucositis, and diarrhea; two patients developed bronchospasm following drug infusions. We conclude that methyl-GAG has major antitumor activity when administered on this schedule to patients with advanced malignant lymphoma. The low degree of toxicity, unique mechanism of action, and minimal myelosuppressive effects suggest that methyl-GAG will prove useful in future trials of combination chemotherapy regimens for the treatment of lymphoma.     

World Workshop on Oral Medicine VI: a systematic review of medication‐induced salivary gland dysfunction

The aim of this paper was to perform a systematic review of the pathogenesis of medication‐induced salivary gland dysfunction (MISGD). Review of the identified papers was based on the standards regarding the methodology for systematic reviews set forth by the World Workshop on Oral Medicine IV and the PRISMA statement. Eligible papers were assessed for both the degree and strength of relevance to the pathogenesis of MISGD as well as on the appropriateness of the study design and sample size. A total of 99 papers were retained for the final analysis. MISGD in human studies was generally reported as xerostomia (the sensation of oral dryness) without measurements of salivary secretion rate. Medications may act on the central nervous system (CNS) and/or at the neuroglandular junction on muscarinic, α‐and β‐adrenergic receptors and certain peptidergic receptors. The types of medications that were most commonly implicated for inducing salivary gland dysfunction were those acting on the nervous, cardiovascular, genitourinary, musculoskeletal, respiratory, and alimentary systems. Although many medications may affect the salivary flow rate and composition, most of the studies considered only xerostomia. Thus, further human studies are necessary to improve our understanding of the association between MISGD and the underlying pathophysiology.     

STRESS FRACTURES OF THE FEMORAL SHAFT IN MILITARY RECRUITS

Stress fractures amongst military recruits are limited to the lower extremities; yet involvement of the shaft of the femur is unusual. Seven such cases in a series of 352 stress fractures are presented. The importance of early recognition and management is emphasized with a view to prevent bony disruption in an otherwise easily treatable condition.KEY WORDS: Fractures stress, Femoral fractures     

Exaggerated feedback control decreases brain serotonin concentration and elicits hyperactivity in a rat model of diet-restriction-induced anorexia nervosa

5-Hydroxytryptamine (5-HT; serotonin) system is the major neurotransmitter system of interest in research on anorexia nervosa (AN). The AN patients show extreme dieting weight loss, hyperactivity and low basal levels of 5-hydroxyindoleacetic acid (5-HIAA), a major metabolite of 5-HT in the cerebrospinal fluid (CSF). Studies on animal models show that diet restriction (DR) decreases 5-HT metabolism in the brain and hypothalamus which is not necessarily associated with a decrease in the availability of essential amino acid tryptophan (TRP) the precursor of serotonin. To further investigate the mechanism involved in DR-induced decreases of 5-HT the present study uses 8-hydroxy-(2-di-n-propylamino) tetralin (8-OH-DPAT), a selective 5-HT-1A agonist, as a probe to monitor the responsiveness of negative feedback control over 5-HT metabolism. Effects of DR and of 8-OHDPAT on TRP, 5-HT and 5-HIAA concentrations are determined in the hypothalamus, a region of the brain known to role in the regulation of appetite. Animals of DR group given access to food 2h daily for 6 days exhibited 21.6% decrease in the body weight compared to freely feeding (FF) controls. The levels of TRP in the plasma and of 5-HT in the hypothalamus decreased. No effect was found on the levels of TRP in the hypothalamus. 8-OH-DPAT-induced decreases of 5-HT and 5-HIAA were greater in DR than FF group. 8-OH-DPAT-induced hyperactivity was also greater in DR than FF group. The results show that DR-induced decreases of 5-HT are due to an increase in the responsiveness of negative feedback control over 5-HT and not due to smaller availability of TRP. DR-induced increase in activity and 8-OH-DPAT-induced greater hyperactivity in DR than FF group may also be due to exaggerated negative feedback control over 5-HT. It is suggested that drugs decreasing the responsiveness of negative feedback control over 5-HT may be of use for the treatment and prevention of AN in under weight patients on restricted diet.     

Vertebral mineral status: assessment with single- versus multi-section CT

A volumetric approach to quantitative single-energy computed tomography (CT) of the spine for trabecular bone evaluation was compared with the accepted single-section method in 32 thoracic and lumbar vertebral bodies from six cadaveric specimens. Both 5-mm and 10-mm contiguous section sequences afforded greater sample volumes, mean mineral equivalent values, and precision than did the single midplane section technique. These findings can be explained by inhomogeneous trabecular distribution, differential bone resorption rates for various cancellous regions, and nonuniform deposition of marrow fat. Scoliosis may modify the net influence of these factors owing to altered biomechanical forces. Although the single-section method affords optimal sensitivity to early or subtle alterations in vertebral trabecular bone density, it may misrepresent the status of the total cancellous volume. Because three-dimensional histographic analysis includes structurally important peripheral trabeculae in determinations of mean mineral equivalent values, it may more accurately reflect vertebral body strength and risk of compression fracture.     

Sternocostoclavicular hyperostosis: a review and report of 11 cases

Sternocostoclavicular hyperostosis is a benign ossifying diathesis of unknown etiology characterized by hyperostosis and soft-tissue ossification between the clavicles, anterior portion of the upper ribs, and manubrium, with variable hyperostosis or ankylosis in the spine and sacroiliac joints. Our cumulative experience with 11 cases is reported, with emphasis on radiographic features of the condition. Scintigraphic results in five patients and computed tomographic findings in one patient are presented. A review of the literature and our own material indicates that sternocostoclavicular hyperostosis may be more common than has been previously recognized.