Direct effect of acute metabolic and respiratory acidosis on parathyroid hormone secretion in the dog.

Because both metabolic (Met Acid) and respiratory acidosis (Resp Acid) have diverse effects on mineral metabolism, it has been difficult to establish whether acidosis directly affects parathyroid hormone (PTH) secretion. Our goal was to determine whether acute Met Acid and Resp Acid directly affected PTH secretion. Three groups of dogs were studied: control, acute Met Acid induced by HCl infusion, and acute Resp Acid induced by hypoventilation. EDTA was infused to prevent acidosis-induced increases in ionized calcium, but more EDTA was needed in Met Acid than in Resp Acid. The PTH response to EDTA-induced hypocalcemia was evaluated also. Magnesium needed to be infused in groups receiving EDTA to prevent hypomagnesemia. The half-life of intact PTH (iPTH) was determined during hypocalcemia when PTH was measured after parathyroidectomy. During normocalcemia, PTH values were greater (p < 0.05) in Met Acid (92 +/- 19 pg/ml) and Resp Acid (77 +/- 22 pg/ml) than in controls (27 +/- 5 pg/ml); the respective pH values were 7.23 +/- 0.01, 7.24 +/- 0.01, and 7.39 +/- 0.02. The maximal PTH response to hypocalcemia was greater (p < 0.05) in Met Acid (443 +/- 54 pg/ml) than in Resp Acid (267 +/- 37 pg/ml) and controls (262 +/- 48 pg/ml). The half-life of PTH was greater (p < 0.05) in Met Acid than in controls, but the PTH secretion rate also was greater (p < 0.05) in Met Acid than in the other two groups. In conclusion, (1) both acute Met Acid and Resp Acid increase PTH secretion when the ionized calcium concentration is normal; (2) acute Met Acid may increase the bone efflux of calcium more than Resp Acid; (3) acute Met Acid acts as a secretogogue for PTH secretion because it enhances the maximal PTH response to hypocalcemia.     

Intraoperative radiotherapy in stage I and II lung cancer

Lung cancer is the leading cause of cancer deaths in both men and women in the United States. Treatment depends on the type and stage of lung cancer. For stage I and II cancer, surgery is usually the treatment of choice. Radiation therapy is used in patients who are considered poor risks for surgical resection. Intraoperative brachytherapy is an effective alternative to external irradiation in this group of patients. From 1958 to 1984, 55 patients with non-small-cell lung cancer were explored at Memorial Sloan Kettering Cancer Center and found to have surgical stage I or II tumors, which were considered to be unresectable mainly because of severe obstructive pulmonary disease precluding adequate resection. All these patients were treated with intraoperative brachytherapy at the time of the thoracotomy. Forty-four percent of these patients received in addition external irradiation, mainly to the mediastinum. The overall 5-year survival calculated by the Kaplan-Meier Method was 32%, and the local disease-free survival was 63%. Cox regression multivariant analysis demonstrated that there is a distinct subgroup with a better prognosis based on tumor site and patient's age--ie, patients who were younger than 58 years of age and had right-side lesions.     

Tuberculosis of the upper limb joints

Summary Seventy-four cases of tuberculosis of the upper limb joints (sterno-clavicular 1; shoulder 12; elbow 42; wrist 10 and fingers 9), treated by two of the authors, were reviewed. Eighty-seven percent presented at an advanced stage of destruction. The diagnosis was proved in 71 out of 74 cases. In most, the treatment was 6–12 months of chemotherapy, plaster immobilization (in order to prevent or correct deformity) and functional rehabilitation whenever possible. The sterno-clavicular and finger joints were not immobilized. Response to chemotherapy was favourable in 66 of the patients followed up. One relapse occurred at the 18th month.The affected shoulder joints healed with loss of movement, but were not painful. At the elbow, ten patients developed spontaneous bony fusion in the right-angle position, 27 had a useful range of motion and 19 had more than 70° of flexion-extension movement. One patient had an arthrodesis. At the wrist, two patients healed with painful stiffness and an arthrodesis was performed. All the finger lesions healed with painless stiffness which did not interfere much with function because rehabilitation had been started early. The authors believe that conservative management usually gives better results than arthrodesis or excision of the joint.

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Résumé Les auteurs rapportent les résultats de leur expérience dans 74 cas d'ostéo-arthrite tuberculeuse du membre supérieur: 1 sterno-claviculaire, 12 scapulo-humérales, 42 coudes, 10 poignets et 9 articulations des doigts, toutes traitées personnellement par les deux auteurs principaux. Sur le plan diagnostique, 87% des patients se présentaient à un stade de destruction avancée. Le diagnostic de certitude fut obtenu dans 71 cas sur 74. Dans la majorité des cas, le traitement a été standardisé: chimiothérapie de 6 à 12 mois, immobilisation plâtrée pour prévenir ou corriger les déformations, suivie de reéducation chaque fois que possible. Les lésions de la sterno-claviculaire et des doigts ne furent pas immobilisées. Les résultats ont été bons en ce qui concerne la chimiothérapie: 66 réponses favorables chez 66 patients suivis. Il y a eu une rechute au 18éme mois. Du point de vue orthopédique, les lésions scapulo-humérales ont guéri avec une raideur de l'épaule toujours importante mais indolore. Au niveau du coude, 10 patients évoluèrent vers la fusion osseuse précoce spontanée, qui se fit à 90° de flexion grâce à l'immobilisation plâtrée; 27 guérirent avec une conservation variable des mouvements du coude dans un secteur fonctionnel et 19 d'entre eux présentaient plus de 70° d'étendue de flexion; 1 patient fut arthrodésé. Au niveau du poignet, 2 patients guérirent avec une raideur douloureuse qui nécessita une arthrodèse. Les lésions des doigts guérirent avec une raideur plus ou moins marquée, bien compensée par la mobilité des autres articulations, conservée intacte par la reéducation. Les auteurs concluent à la meilleure qualité des résultats du traitement conservateur que des classiques interventions d'arthrodèse ou de résection articulaire.

     

Klinische Erfahrungen mit der Knorpel-Knochen-Transplantation

The treatment of deep cartilage defects in load-bearing joints is a problem that still has no satisfactory solution. Full-thickness defects of the articular cartilage rarely heal spontaneously, usually leaving damage that can lead to early arthrosis. Techniques currently available for the treatment of chondral defects include abrasion, drilling, micro-fracturing, transplantation of tissue autografts and allografts, and cell transplantation. Osteochondral autograft transplantation is currently the only surgical cartilage repair technique known to lead to the formation of genuine hyaline articular cartilage and its retention at least in the medium term. The Draenert method, in which a water-cooled diamond bone-cutting system is used, is an effective procedure for resurfacing the joints affected by localised cartilaginous defects, even when there is also severe bone loss. Donor-side morbidity can be kept to a minimum by filling the defect caused by harvesting with a press-fit cylinder of cancellous bone covered with periosteum for protection.     

De-novo expression of vascular ecto-5′-nucleotidase and down-regulation of glomerular ecto-ATPase in experimental chronic renal transplant failure

Ischemic injury plays an important role in chronic renal transplant failure (CRTF). Down-regulation of ecto-adenosine triphosphatase (ATPase) in combination with up-regulation of ecto-5'-nucleotidase is a hallmark of ischemic injury. We studied the expression of renal ecto-5'-nucleotidase and ecto-ATPase in experimental renal transplantation. Fisher 344-to-Lewis allografted rats were either treated with an angiotensin-converting enzyme inhibitor (ACEi) or left untreated. Lewis-to-Lewis syngrafted rats served as controls. Untreated allografted rats developed proteinuria, glomerulosclerosis, and mild intimal hyperplasia. ACEi completely prevented focal and segmental glomerulosclerosis (FGS) and proteinuria, but significantly enhanced intimal hyperplasia. Untreated allografted rats revealed marked vascular ecto-5'-nucleotidase activity, which increased with ACEi. Vascular ecto-5'-nucleotidase activity was absent in syngrafted animals. Ecto-5'-nucleotidase activity correlated well with intimal hyperplasia. Glomerular ecto-ATPase expression was significantly reduced in untreated allografted rats compared to syngrafted rats and correlated well with the extent of FGS. ACEi prevented reduction in glomerular ecto-ATPase. We found de-novo expression of ecto-5'-nucleotidase at sites of renal intimal hyperplasia. Glomerular ecto-ATPase expression was markedly reduced in allografted rats and was prevented by ACEi. These enzyme expression patterns suggest local ischemic damage in experimental CRTF.     

The concept of culture: A core issue in health disparities

Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors.