Cytotoxic activity of human pulmonary alveolar macrophages.

The functions of human pulmonary alveolar macrophages (PAMs) have been relatively little studied compared with those of their circulating counterparts, blood monocytes. This study examined the ability of human PAMs to kill primary human tumor cell cultures and control normal fibroblasts in vitro. PAMs were derived by bronchial lavage from patients with lung cancer of various histological types and stages, patients with acute or chronic noncancerous pulmonary disorders, and subjects with a presumed illness who proved to be normal. After extensive washing, the PAMs were cocultured with [3H]proline-labeled tumor cells, principally lung cancers and melanomas, at various effector:target ratios for 60 hr. Cytotoxicity was measured by comparing radioactivity associated with the remaining adherent tumor cells cultured in the presence or absence of PAMs. Twenty-eight of 42 preparations of PAMs from 42 individuals were cytotoxic to one or more short-term primary tumor cultures. All 28 specimens from patients with lung cancer or chronic pulmonary disease were cytotoxic; all of the 14 PAM preparations lacking cytotoxicity were from individuals with acute pulmonary disorders or who were proved free of pulmonary disease. PAMs were cytotoxic even at effector:target ratios of 2.5:1 or 1.25:1. Fibroblasts were unaffected at any ratio. Sarcoidosis patients in remission had noncytotoxic PAMs, whereas the disease in relapse was characterized by cytotoxic PAMs. Serial study of 2 patients confirmed a loss of reactivity during remission. Smoking did not correlate with the presence or absence of spontaneous cytotoxicity and did not influence the degree of cytotoxicity in "reactors." Partially purified alpha-interferon enhanced the killing of cytotoxic PAMs in 10 of 21 instances but did not induce cytotoxicity in 9 tests on nonreactive PAMs. We conclude that human PAMs from patients with lung cancer or chronic pulmonary diseases, including active sarcoidosis, were cytotoxic to several recently explanted tumor cell cultures. PAMs from acute pulmonary dysfunctions and those from patients with inactive sarcoidosis were not spontaneously cytotoxic.

Effect of long-distance running on bone mass in women.

The effect of long-distance running on bone mass was assessed in 10 premenopausal and 9 estrogen-deprived postmenopausal women and compared to that in closely matched sedentary control women. Vertebral trabecular bone density (VBD) was determined by computed tomography and radial cortical bone density (CBD) by single-photon absorptiometry. Physical fitness was assessed by determining maximal oxygen consumption (VO2max) on a treadmill run to exhaustion. VBD was 183 +/- 7 mg/cm3 and VO2max was 48 +/- 1 ml/kg per minute in young women runners and 163 +/- 8 mg/cm3 and 32 +/- 2 ml/kg per minute in sedentary young women. A positive correlation was noted between VBD and VO2max in these groups (r = 0.509, p less than 0.03). Despite a significantly higher VO2max in postmenopausal women runners compared with sedentary controls (37 +/- 2 versus 24 +/- 2 ml/kg per minute), VBD was identical (112 +/- 5 versus 111 +/- 5 mg/cm3) and no correlation was seen between VBD and VO2max (r = 0.187, p = 0.457). Radial cortical bone density was not different between the runners or sedentary groups in young women (0.738 +/- 0.01 versus 0.732 +/- 0.1 g/cm2) or postmenopausal women (0.617 +/- 0.3 versus 0.665 +/- 0.4 g/cm2). These results suggest that although physical fitness enhances vertebral bone density in premenopausal women, it does not appear to prevent age- and/or sex steroid deficiency-induced bone loss in postmenopausal women.

Adult respiratory distress syndrome following administration of lidocaine.

A patient twice developed the adult respiratory distress syndrome following an adverse reaction to administration of lidocaine. To our knowledge, such an association has not been reported previously.

Hypertrophic cardiomyopathy in a college athlete.

The greatest catastrophy in sports is an athlete's unexpected sudden death. Identifying those athletes at risk remains a great challenge to physicians performing preseason examinations. Hypertrophic cardiomyopathy is the most common cause of nontraumatic sudden death in athletes. Most cases of this diseased heart are diagnosed easily by echocardiography. The case presented exemplifies the attention to detail required to differentiate the borderline diseased heart from the conditioned athletic heart. Once a diagnosis of hypertrophic cardiomyopathy is made, further participation in intense physical exercise is discouraged. This recommendation is necessary despite the unknown relative sudden death risk for the minimal criteria cases.

Foot injuries of the recreational athlete.

Adult recreational athletes, or 'weekend warriors,' are vulnerable to foot injuries such as Achilles tendon ruptures, plantar fasciitis, retrocalcaneal bursitis, midfoot tendinitis, metatarsal stress fractures, and interdigital neuroma. Physicians also need to be alert for less common injuries such as Jones fractures and tarsal navicular stress fractures because of the risk of delayed healing or nonunion. Many foot injuries can be treated conservatively, but some Achilles tendon ruptures, Jones fractures, and tarsal navicular stress fractures may require surgery.

Vocal cord dysfunction: don't mistake it for asthma.

Vocal cord dysfunction (VCD), with its symptoms of stridor, air hunger, and chest or throat tightness, occurs primarily in active adolescents and young adults and may mimic exercise-induced asthma. Suspicions of VCD will be borne out by a mostly inspiratory stridor, abrupt onset and resolution of symptoms, an unpredictable symptom pattern, and the failure of usual asthma medications to resolve attacks. Laryngoscopy during acute symptoms is the definitive diagnostic tool. Panting can often stop an attack, and preventive treatment consists of patient education, speech therapy, and, when needed, psychological measures.

Preventing Sudden Death.

In brief To address the leading cause of brief sudden death in high school and college athletes, the sports medicine team can consider using automated external defibrillators. When incorporated into an emergency response plan, these devices have dramatically improved cardiac arrest survival rates. Issues to review carefully include safety, efficacy, personnel training, medical control, pertinent regulations, and cost.

The case for the hospital staff attorney.

A full-time staff attorney offers a hospital substantial advantages over an outside attorney, including availability, accessibility, and total familiarity with hospital operations. Among the services that a staff attorney can perform are advising the governing body, reviewing contracts, participating in risk management, providing liaison with outside counsel, and responding to requests for release of information.

Actions of the Kunitz-type serine protease inhibitor Amblyomin-X on VEGF-A-induced angiogenesis.

Amblyomin-X is a Kunitz-type serine protease inhibitor (Kunitz-type SPI) designed from the cDNA library of the Amblyomma cajennense tick, which displays in vivo anti-tumor activities. Here, the mechanisms of actions of Amblyomin-X in vascular endothelial growth factor A (VEGF-A)-induced angiogenesis were characterized. Topical application of Amblyomin-X (10 or 100 ng/10 µl; each 48 h) inhibited VEGF-A-induced (10 ng/10 µl; each 48 h) angiogenesis in the dorsal subcutaneous tissue in male Swiss mice. Moreover, similar effect was observed in the VEGF-A-induced angiogenesis in the chicken chorioallantoic membrane (CAM). Additional in vitro assays in t-End cells showed that Amblyomin-X treatment delayed the cell cycle, by maintaining them in G0/G1 phase, and inhibited cell proliferation and adhesion, tube formation and membrane expression of the adhesion molecule platelet-endothelial cell adhesion molecule-1 (PECAM-1), regardless of mRNA synthesis. Together, results herein reveal the role of Kunitz-type SPI on in vivo VEGF-A-induced angiogenesis, by exerting modulatory actions on endothelial cell proliferation and adhesion, especially on membrane expression of PECAM-1. These data provide further mechanisms of actions of Kunitz-type SPI, corroborating their relevance as scientific tools in the design of therapeutic molecules.

Tarsal navicular stress fracture in a young athlete: case report with clinical, radiologic, and pathophysiologic correlations.

BACKGROUND: Tarsal navicular fractures are uncommon but important causes of foot pain. Being alert to this condition can help prevent a delay in the diagnosis. METHODS: A literature search of MEDLINE was undertaken, and a case report of an adolescent with tarsal navicular stress fracture is described. RESULTS AND CONCLUSIONS: Tarsal navicular fractures are often misdiagnosed for months. Because plain radiographs are unreliable, the diagnosis of tarsal navicular fractures requires the use of bone scan, fine-cut computed tomographic scans, or magnetic resonance imaging. Treatment requires strict non-weight-bearing activities to avoid complications. When the alert primary care physician can diagnose this condition, treatment of tarsal navicular fractures can be effective and rewarding.

Idiopathic thrombocytopenic purpura in children.

Idiopathic thrombocytopenic purpura in children 10 years of age or younger was observed to have a more favorable prognosis than in older children. Corticosteroid therapy in children judged to be at increased risk of serious hemorrhage resulted in a significantly greater number of patients with an early increase in platelets than was noted in a control group. All patients with chronic disease who responded to administration of a corticosteroid initially and then relapsed had some response to a subsequent course of therapy, although none had a sustained remission. In such patients, splenectomy was a more effective therapeutic measure than treatment with either a corticosteroid or a cytotoxic agent.

Oviposition and eclosion periods of Ixodes didelphidis Fonseca and Aragão, 1951 (Acari: Ixodidae) under laboratory conditions.

Oviposition and eclosion periods for Ixodes didelphidis were observed under two temperatures (25 degrees C and 27 degrees C) and 90-95% humidity. Although there was a significant increase in the eclosion period (p<0.05) and a tendency to increase the oviposition period at 25 degrees C, there was neither significant differences in the interval (days), until maximum peak of eclosion nor in the number of emerging larvae during the peak nor the total number of emerged larvae. These temperature values are not critical for embryological development of the species. Because at 27 degrees C and under high humidity the oviposition and eclosion periods are shorter, and the percentage of emerged larvae is higher, we consider this to be the ideal temperature for laboratory studies.