Deterioration of Performance Status during Palliative Radiotherapy Suggests a Significant Short Survival Duration: Indicating the Necessities for Considering Radiotherapy Discontinuation

Discontinuation of palliative radiotherapy due to a patient's declining general condition poses a clinical dilemma for palliative care physicians. This study aimed to investigate the survival duration of patients whose performance status (PS) deteriorated during palliative radiotherapy and inform decisions regarding early treatment discontinuation. We retrospectively analyzed data from patients referred from our institute's palliative care department who underwent ≥10 fractions of palliative radiotherapy between March 2017 and December 2021. PS was assessed using the Eastern Cooperative Oncology Group (ECOG) scale. Survival duration was calculated from the final day of palliative radiotherapy to death using the Kaplan-Meier method. A total of 35 patients underwent palliative radiotherapy. Seven (20%) experienced deterioration in ECOG PS during treatment. Their median survival duration was significantly shorter at 22 days (95% confidence interval: 1-94 days) compared to 125 days (95% confidence interval: 82-150 days) for the 28 patients whose PS remained stable (p = 0.0007). Deterioration in ECOG PS during palliative radiotherapy signifies a markedly shorter survival duration. Careful assessment of a patient's condition throughout treatment is crucial, and early discontinuation should be considered if their general health worsens rather than strictly adhering to the initial schedule.

[Ectopic Adrenocorticotropic Hormone-Producing Pulmonary Carcinoid Presenting as Cushing's Syndrome after Intrapleural Hyperthermic Chemotherapy]

The patient was a woman in her 70's was referred to our hospital because of an abnormal shadow on chest roentgenogram at an annual medical checkup. Since preoperative examinations suggested lung cancer in the right middle lobe, thoracoscopic right middle lobectomy was planned. However, pleural dissemination was detected at surgery and we changed the treatment plan to the intrapleural hyperthermic chemotherapy. During the postoperative course, facial edema, hypokalemia, and hyperglycemia developed, and the diagnosis of Cushing's syndrome was suggested based on an increase in serum level of adrenocorticotropic hormone (ACTH) and cortisol, and was confirmed by a dexamethasone suppression test. Intrapleural hyperthermic chemotherapy was likely to collapse the ACTH-producing tumor leading Cushing's syndrome.

Diagnostic performance of serum interferon gamma, matrix metalloproteinases, and periostin measurements for pulmonary tuberculosis in Japanese patients with pneumonia

Serum markers that differentiate between tuberculous and non-tuberculous pneumonia would be clinically useful. However, few serum markers have been investigated for their association with either disease. In this study, serum levels of interferon gamma (IFN-γ), matrix metalloproteinases 1 and 9 (MMP-1 and MMP-9, respectively), and periostin were compared between 40 pulmonary tuberculosis (PTB) and 28 non-tuberculous pneumonia (non-PTB) patients. Diagnostic performance was assessed by analysis of receiver-operating characteristic (ROC) curves and classification trees. Serum IFN-γ and MMP-1 levels were significantly higher and serum MMP-9 levels significantly lower in PTB than in non-PTB patients (p < 0.001, p = 0.002, p < 0.001, respectively). No significant difference was observed in serum periostin levels between groups. ROC curve analysis could not determine the appropriate cut-off value with high sensitivity and specificity; therefore, a classification tree method was applied. This method identified patients with limited infiltration into three groups with statistical significance (p = 0.01), and those with MMP-1 levels < 0.01 ng/mL and periostin levels ≥ 118.8 ng/mL included only non-PTB patients (95% confidence interval 0.0–41.0). Patients with extensive infiltration were also divided into three groups with statistical significance (p < 0.001), and those with MMP-9 levels < 3.009 ng/mL included only PTB patients (95% confidence interval 76.8–100.0). In conclusion, the novel classification tree developed using MMP-1, MMP-9, and periostin data distinguished PTB from non-PTB patients. Further studies are needed to validate our cut-off values and the overall clinical usefulness of these markers.

Analysis of gastrointestinal metastasis of primary lung cancer: Clinical characteristics and prognosis

The prevalence of gastrointestinal metastasis of lung cancer is low. The aim of the present study was to analyze the frequency and clinical characteristics of metastases to the gastrointestinal tract by retrospectively assessing the clinical records of 2,066 patients with lung cancer. A total of 7 patients (0.33%) were diagnosed with gastrointestinal metastasis, including 4 patients with adenocarcinoma, 1 patient with large cell carcinoma and 2 patients with pleomorphic carcinoma. Furthermore, 3 of the patients presented with small bowel metastases, 2 with gastric metastases, 1 with large bowel metastasis and 1 with metastasis of the appendix. The mean time between the diagnosis of the lung tumors and the identification of gastrointestinal metastasis was 13.5 months (range, 3-49 months). The mean time between the identification of the gastrointestinal metastasis and mortality was 100.6 days (range, 21-145 days). In conclusion, the prognosis of patients with recurrence in distant organs, including the gastrointestinal tract, may be worse than patients with recurrence in distant organs, excluding the gastrointestinal tract, particularly those with symptomatic gastrointestinal metastasis. Therefore, the presence of clinical gastrointestinal metastasis may be life threatening; comprehensive evaluations are required to detect and monitor gastrointestinal metastasis during follow-up.

Comparison of clinical and pathological features of lung lesions of systemic IgG4-related disease and idiopathic multicentric Castleman's disease

AIMS

The lung lesion [immunoglobulin (Ig)G4-L] of IgG4-related disease (IgG4-RD) is a condition that occurs together with IgG4-RD and often mimics the lung lesion [idiopathic multicentric Castleman's disease (iMCD-L)] of idiopathic multicentric Castleman's disease (iMCD). Because no clinical and pathological studies had previously compared features of these diseases, we undertook this comparison with clinical and histological data.

METHODS AND RESULTS

Nine patients had IgG4-L (high levels of serum IgG4 and of IgG4⁺ cells in lung specimens; typical extrapulmonary manifestations). Fifteen patients had iMCD-L (polyclonal hyperimmunoglobulinaemia, elevated serum interleukin-6 levels and polylymphadenopathy with typical lymphadenopathic lesions). Mean values for age, serum haemoglobin levels and IgG4/IgG ratios were higher in the IgG4-L group and C-reactive protein levels were higher in the iMCD-L group. All IgG4-RD lung lesions showed myxomatous granulation-like fibrosis (active fibrosis), with infiltration of lymphoplasmacytes and scattered eosinophils within the perilymphatic stromal area, such as interlobular septa and pleura with obstructive vasculitis. All 15 lung lesions of iMCD, however, had marked accumulation of polyclonal lymphoplasmacytes in lesions with lymphoid follicles and dense fibrosis, mainly in the alveolar area adjacent to interlobular septa and pleura without obstructive vasculitis.

CONCLUSIONS

Although both lesions had lymphoplasmacytic infiltration, lung lesions of IgG4-RD were characterized by active fibrosis with eosinophilic infiltration within the perilymphatic stromal area with obstructive vasculitis, whereas lung lesions of iMCD had lymphoplasmacyte proliferating lesions mainly in the alveolar area adjacent to the perilymphatic stromal area. These clinicopathological features may help to differentiate the two diseases.

Glucocorticoid Therapy and the Risk of Infection in Patients With Newly Diagnosed Autoimmune Disease

Glucocorticoid (GC) therapy is associated with the risk of life-threatening adverse events in patients with autoimmune disease. To determine accurately the incidence and predictors of GC-related adverse events during initial GC treatment, we conducted a cohort study. Patients with autoimmune disease who were initially treated with GCs in Japan National Hospital Organization (NHO) hospitals were enrolled. Cox proportional hazard regression was used to determine the independent risks for GC-related serious adverse events and mortality. Survival was analyzed according to the Kaplan-Meier method and was assessed with the log-rank test.The 604 patients had a total follow-up of 1105.8 person-years (mean, 1.9 year per patient). One hundred thirty-six patients had at least 1 infection with objective confirmation, and 71 patients had serious infections. Twenty-two cardiovascular events, 55 cases of diabetes, 30 fractures, 23 steroid psychosis events, and 4 avascular bone necrosis events occurred during the follow-up period. The incidence of serious infections was 114.8 (95% confidence interval, 95.7-136.6) per 1000 person-years. After adjustment for covariates, the following independent risk factors for serious infection were found: elderly age (hazard ratio [HR], 1.25/10-yr age increment; p = 0.016), presence of interstitial lung disease (HR, 2.01; p = 0.011), high-dose GC use (≥29.9 mg/d) (HR, 1.71; p = 0.047), and low performance status (Karnofsky score, HR, 0.98/1-score increment; p = 0.002). During the follow-up period, 73 patients died, 35 of whom died of infection. Similarly, elderly age, the presence of interstitial lung disease, and high-dose GC use were found to be significant independent risk factors for mortality. The incidence of serious and life-threatening infection was higher in patients with autoimmune disease who were initially treated with GCs. Although the primary diseases are important confounding factors, elderly age, male sex, the presence of interstitial lung diseases, high-dose GCs, and low performance status were shown to be risk factors for serious infection and mortality.

Addison's disease due to tuberculosis that required differentiation from SIADH

A 77-year-old man was admitted to our hospital complaining of general fatigue. Serum sodium was 116 mEq/l and serum antidiuretic hormone (ADH) was elevated. Radiologic examination revealed nodules in the brain as well as in both adrenal glands. Based on the findings of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET), we had considered that the cause of the hyponatremia was syndrome of inappropriate secretion of antidiuretic hormone (SIADH) due to active extrapulmonary tuberculosis. Against our expectations, the patient's condition got worse just after he began antituberculous therapy; we finally diagnosed Addison's disease by additional hormonal tests. His condition recovered immediately with the administration of high-dose hydrocortisone, and the tuberculous lesions became smaller with antituberculous medications. Although tuberculous Addison's disease has been decreasing markedly in recent years, we have to consider the possibility of adrenal insufficiency when hyponatremia is observed in patients with active tuberculosis or those having a past history of tuberculosis.

[Primary pulmonary Hodgkin lymphoma--two case reports and a review of the literature]

Primary extranodal involvement of Hodgkin lymphoma (HL) is rare. We report two HL patients presenting with exclusive or predominant lung involvement. In both cases, the results of transbronchial and/or CT-guided lung needle biopsy were indicative of granulomatous disease. Eventually, lymph node biopsy specimens revealed HL with nodular sclerosis type and lymphocyte-rich type, respectively. There were no specific symptoms, laboratory and imaging findings for pulmonary HL. A histological examination was required to confirm the diagnosis. Lung biopsy techniques such as transbronchial or percutaneous biopsy may be insufficient to allow diagnosis of HL. Pulmonary HL should be included in the differential diagnosis of lung involvement, even when the pathological evaluation of nonspecific inflammation was made from the biopsied specimens.

Pulmonary Dirofilariasis

OBJECTIVE

The purpose of this study was to describe the computed tomography (CT) and pathologic features of 5 nodules of pulmonary dirofilariasis in 4 patients.

METHODS

Four patients with 5 nodules of pathologically confirmed pulmonary dirofilariasis who under went CT were enrolled, and the imaging interpretations were retrospectively compared with the histopathologic characteristics.

RESULTS

Three of the 4 patients had a solitary nodule, and the remaining patient had 2 nodules. All the nodules were distributed in the right lower lobe and were attached to the pleura. They were all round or oval in shape and ranged in size from 11 to 22 mm in largest diameter (mean=17 mm). On thinner section CT, the nodules had a well-defined smooth margin with or without a shallow notch; they were connected to the arterial branch and, occasionally, to the venous branch. On contrast-enhanced CT, all the nodules contained a homogeneous low-attenuation area, which corresponded to areas of coagulative necrosis on histopathologic examination.

CONCLUSION

Although the CT findings of a pulmonary dirofilariasis nodule are nonspecific, awareness of the findings on contrast-enhanced CT and the pathologic appearance of this rare benign condition may facilitate its differentiation from a malignant nodule.

High plasma osteopontin level and its relationship with interleukin-12-mediated type 1 T helper cell response in tuberculosis

Osteopontin (OPN, also known as Eta-1), a noncollagenous matrix protein produced by macrophages and T lymphocytes, is expressed in granulomatous lesions caused by Mycobacterium tuberculosis infection. In the present study, we compared plasma concentrations of OPN in patients with active pulmonary tuberculosis with those of healthy control subjects and patients with sarcoidosis, another disease associated with granuloma formation. Plasma OPN levels were significantly higher in patients with tuberculosis (n = 48) than in control subjects (n = 34) and patients with sarcoidosis (n = 20). OPN levels correlated well with severity of pulmonary tuberculosis, as indicated by the size of lung lesions on chest X-ray films. Furthermore, chemotherapy resulted in a significant fall in plasma OPN levels. In patients with tuberculosis, plasma OPN concentrations correlated significantly with those of interleukin (IL)-12. In vitro experiments showed that OPN production by peripheral blood mononuclear cells infected with Mycobacterium bovis bacillus Calmette-Guérin preceded the synthesis of IL-12 and interferon-gamma and that the neutralizing anti-OPN monoclonal antibody significantly reduced the production of IL-12 and interferon-gamma. Our results suggest that OPN may be involved in the pathologic process associated with active pulmonary tuberculosis by inducing IL-12-mediated type 1 T helper cell responses.

Elastic anisotropy and collagen orientation of osteonal bone are dependent on the mechanical strain distribution

There is evidence that the collagen microarchitecture of bone is influenced by mechanical stresses or strains. We hypothesized that peak functional strains correlate with the elastic anisotropy and collagen orientation of bone tissue and that the bone anisotropy might be changed by altering the strain patterns in canine radii for 12 months. We tested these hypotheses in studies using nine adult foxhounds. The baseline group (n = 3) had three rosette strain gauges placed around the midshaft of the radius, and strain distributions were measured during walking. The osteotomy group (n = 3) had 2 cm of the ulna surgically removed, and the sham group (n = 3) received a sham osteotomy. The osteotomy and sham groups were allowed free movement in cages with runs for 12 months, after which strain distributions were measured on the radii during walking. Bone-tissue anisotropy and collagen architecture were measured in radii from which the in vivo longitudinal strain patterns had been measured. The collagen birefringence patterns were measured with use of a circularly polarized light technique, and the elastic anisotropy of the bone, mineral, and collagen matrix was evaluated with a novel acoustic microscopy technique. Peak longitudinal strains in the radius correlated with the normalized longitudinal structure index (a polarized light measure of collagen birefringence) and the tissue anisotropy ratio. The average anisotropy ratio was 1.28+/-0.01 in the posterior (compressive) cortex and 1.43+/-0.01 in the anterior (tensile) cortex (these values are significantly different at p < 0.0001). The ulnar osteotomy changed the strain pattern on the radius, causing increased tensile strains in the medial cortex by more than 5-fold that were associated with a significant increase in the anisotropy ratio in the bone tissue. The longitudinal structure index was strongly correlated (r = 0.62, p < 0.005) with the anisotropy ratio of demineralized bone but was not correlated with that of deproteinized bone; this indicates that it reflects collagen fibril orientation in the bone matrix. These results indicate that mechanical strains affect both collagen and mineral microarchitecture in bone tissue, i.e., tensile strains are associated with increased tissue anisotropy and compressive strains, with decreased anisotropy.

Recruitment and proliferative responses of osteoblasts after mechanical loading in vivo determined using sustained-release bromodeoxyuridine

Mechanical bending of a rat's tibia in vivo can increase endocortical bone formation by over sixfold. It has been proposed that mechanical loading increases bone formation by driving osteoprogenitor cells in the marrow stroma to progress through the cell cycle and subsequently differentiate into osteoblasts at the cortical bone surfaces. We used a sustained-release preparation of 5-bromo-2'-deoxyuridine (SR-BrdUrd) to determine the origin of endocortical osteoblasts in rat tibiae after mechanical loading. SR-BrdUrd was bioavailable for the entire 96 h duration of the experiments, so all cells that progressed through a cell cycle were labeled with BrdUrd. Although the endocortical osteoblast surface was significantly increased (p < 0.05) at 48 h after loading, the percentage of BrdUrd-labeled osteoblasts did not increase, suggesting that the newly differentiated osteoblasts on the endocortical surface did not originate from proliferating cells. At 96 h after loading, 30-40% of the endocortical osteoblasts were BrdUrd labeled. The majority of BrdUrd-labeled osteoblasts appeared on the endocortical bone surface within the third day after loading, indicating that proliferation and differentiation of precursors into endocortical osteoblasts required 72 h after the loading stimulus. These results indicate that mechanical loading can cause two distinct osteoblastic responses: an immediate response within 48 h in which osteoblasts are recruited from nondividing preosteoblasts and/or bone-lining cells, and a delayed response involving proliferation and differentiation of preosteoblasts that requires > or =3 days.

Effects of nitric oxide synthase inhibitors on bone formation in rats

NO is synthesized from L-arginine by at least three isoforms of nitric oxide synthase (NOS) and is known to function as a vasodilator and neurotransmitter. NO is produced by bone cells but its function in bone biology is, as yet, unclear. We hypothesized that NOS mediates bone formation in remodeling regions of the skeleton. We studied the effects of two NOS inhibitors: N(G)-nitro-L-arginine methyl ester (L-NAME), which is a general inhibitor of NOS activity and is known to inhibit the vasodilatory effects of the endothelial NOS (eNOS) isoform; and aminoguanidine, which is a selective inhibitor of the inducible NOS (iNOS) isoform. Our hypothesis was tested by treating rats with NOS inhibitors and measuring bone formation rates in the tibial epiphysis and diaphysis. Bone formation indices were measured using standard bone histomorphometry. L-NAME treatment significantly raised mean arterial blood pressure (MAP). This effect was partially reversed by addition of L-arginine. Aminoguanidine had no significant effect on MAP, indicating that it did not block eNOS. The treatments also had substantial effects on bone formation in remodeling trabecular bone. L-NAME did not significantly change trabecular bone formation rate, whereas aminoguanidine reduced bone formation rate in the tibial epiphysis by 79% compared with control. This reduction was completely reversed by L-arginine, suggesting that bone formation during remodeling is, in part, mediated through L-arginine metabolism. No effect of aminoguanidine on bone formation was seen in the tibial diaphysis, a site that undergoes minimal bone remodeling. This finding suggests that the L-arginine-NO pathway is important in bone remodeling.

Mechanotransduction in bone: osteoblasts are more responsive to fluid forces than mechanical strain

Mechanical force applied to bone produces two localized mechanical signals on the cell: deformation of the extracellular matrix (substrate strain) and extracellular fluid flow. To study the effects of these stimuli on osteoblasts, MC3T3-E1 cells were grown on type I collagen-coated plastic plates and subjected to four-point bending. This technique produces uniform levels of physiological strain and fluid forces on the cells. Each of these parameters can be varied independently. Osteopontin (OPN) mRNA expression was used to assess the anabolic response of MC3T3-E1 cells. When fluid forces were low, neither strain magnitude nor strain rate was correlated with OPN expression. However, higher-magnitude fluid forces significantly increased OPN message levels independently of the strain magnitude or rate. These data indicate that fluid forces, and not mechanical stretch, influence OPN expression in osteoblasts and suggest that fluid forces induced by extracellular fluid flow within the bone matrix may play an important role in bone formation in response to mechanical loading.

High fluoride intakes cause osteomalacia and diminished bone strength in rats with renal deficiency

Renal insufficiency is known to increase plasma fluoride levels, which may increase the risk of fluorosis and osteomalacia. The purpose of this study was to determine the effects of fluoride on skeletal fragility and mineralization in renal-deficient animals. We evaluated the skeleton of rats with surgically induced renal deficiency (4/5 nephrectomy) that were chronically exposed to fluoridated water at concentrations of 0, 5, 15, and 50 ppm for a period of 6 months. The chosen fluoride doses caused plasma fluoride levels equivalent to those in humans consuming fluoridated water levels of 0, 1, 3, and 10 ppm, respectively. Animals with renal deficiency drank about 60% more water and excreted 85% more urine than control animals. Glomerular filtration rate (GFR) was decreased 68% and plasma BUN was increased fourfold in rats with renal deficiency. Plasma fluoride was strongly correlated with 1/GFR and was greatly increased by renal deficiency in all animals consuming fluoridated water. There was a strong positive, nonlinear relationship between plasma fluoride and bone fluoride levels, suggesting nonlinear binding characteristics of fluoride to bone. The amount of unmineralized osteoid in the vertebral bone was related to the plasma fluoride levels. Vertebral osteoid volume was increased over 20-fold in animals with renal deficiency that received 15 or 50 ppm fluoride, suggesting osteomalacia. Should osteomalacia be defined as a tenfold increase in osteoid volume, there appeared to be a threshold plasma fluoride level of about 20 micromol/L, above which osteomalacia was observed consistently. This plasma fluoride level was not achieved in control rats regardless of fluoride intake, nor was it achieved in renal-deficient rats receiving 0 or 5 ppm fluoride. A fluoride concentration of 50 ppm reduced femoral bone strength by 11% in control rats and by 31% in renal-deficient rats. Vertebral strength also was decreased significantly in renal-deficient rats given 50 ppm fluoride. In conclusion, fluoridated water in concentrations equivalent to 3 and 10 ppm in humans, caused osteomalacia and reduced bone strength in rats with surgically-induced renal deficiency.

Advantages of raloxifene over alendronate or estrogen on nonreproductive and reproductive tissues in the long-term dosing of ovariectomized rats

For the first time, raloxifene or alendronate was administered to rats immediately after ovariectomy for 10 months and compared with estrogen to elucidate mechanisms behind the raloxifene effects observed in nonreproductive and reproductive tissues. Specifically, 75-day-old rats were randomly selected as sham controls (Sham), ovariectomized controls (Ovx) or ovariectomized rats treated with fully efficacious doses of raloxifene (RA), 17 alpha-ethynyl estradiol (EE2) or alendronate (ABP). Lumbar vertebrae and proximal tibiae were examined by computed tomography (QCT) and by histomorphometry. Histomorphometry showed differences in bone architecture between groups when QCT densities were similar, but tibial trabecular bone analysis by QCT correlated with histomorphometry with r = .86 to .93, depending on the parameter. Both techniques confirmed that Ovx had substantially less bone than Sham, with greater loss of trabecular bone in the proximal tibia than vertebrae. Both techniques showed that RA had effects similar to but not identical with EE2 in preventing bone loss in vertebrae and tibiae. ABP partially prevented loss of bone in L-5, but was not significantly different from Ovx in the proximal tibia. This may be caused by ABP suppression of bone apposition, beyond effects observed for EE2 or RA. RA appeared to be more similar to EE2 because ABP significantly depressed bone formation (bone formation rate, mineral apposition rate) to below RA or EE2 levels, especially in L-5. Mechanical loading to failure of L-6 vertebrae showed a rank order of vertebral strength of Sham > RA > EE2 > Ovx > ABP, although significant differences were not observed between treatment groups. These data show that ABP suppression of bone formation can affect bone quality with long-term treatment. In other tissues, RA had minimal uterine effects, while significantly lowering serum cholesterol to below EE2-treated levels. Both EE2 and RA rats had significantly lower body weights than the other groups. ABP had no effect on serum lipids, uterine weight or body weight. Therefore, RA appears to have a broader range of desirable effects on bone, body weight, uteri and cholesterol than ABP or EE2 in ovariectomized rats.

Nitric oxide inhibitor L-NAME suppresses mechanically induced bone formation in rats

We hypothesized that nitric oxide may act as an intermediary in the transduction of mechanical loading of bone into a bone formation response. In the present study, 48 rats were divided into the following three treatment groups: control, treatment with N omega-nitro-L-arginine methyl ester (L-NAME; an inhibitor of nitric oxide synthase), and treatment with D-NAME (the less active enantiomer of L-NAME). The rats were subdivided into groups subjected to four-point bending or sham loading of their right tibiae. Bone formation was measured at the midshaft of the loaded and nonloaded (left) tibiae of each rat using histomorphometric methods. The application of four-point bending, but not sham loading, resulted in new bone formation. Treatment with L-NAME reduced the rate of mechanically induced bone formation by 66% compared with the control group. Bone formation rates in nonloaded or sham-loaded limbs were not affected by L-NAME treatment. The results suggest that nitric oxide may play a role in the transduction of a mechanical stimulus into a biological response in bone.

Increased bone formation in rat tibiae after a single short period of dynamic loading in vivo

Based on our quantum concept for mechanically adaptive bone formation, we hypothesized that a single bout of loading would increase bone formation at the endosteal surface in rat tibiae, with a maximal response 4-8 days after loading and a stimulus-response relationship for load magnitude. Bending loads were applied to right tibiae of rats at 31, 43, 53, or 65 N for a single bout of 36 or 360 cycles; bone formation was assessed 1-4, 5-8, or 9-12 days after loading. A single loading episode increased lamellar bone formation rate (BFR) in all groups (P<0.05) and was maximal 5-8 days after loading. A distinct dose-response relationship was not evident among all load magnitudes or for duration, but 65 N was significantly more osteogenic than loads of 31-53 N (P<0.05), consistent with a threshold response to loading. There was also evidence for a significant increase in BFR (P<0.05) and double-labeled surface (P<0.01) within 4 days of loading, suggesting that bone-lining cells were activated directly by the stimulus. Thus subtle changes in BFR may occur by modulating the activity of surface cells, but large modeling drifts and anabolic responses require recruitment and differentiation of osteoprogenitor cells near the bone surface.

Aging changes mechanical loading thresholds for bone formation in rats

The effect of aging on the mechanical loading thresholds for osteogenesis was investigated in rats. We applied mechanical loads varying from 30 to 64 N to the tibiae of 43 19-month-old rats using a four-point bending apparatus. Bone formation rates were measured on the periosteal and endocortical surfaces of the tibial midshaft using double-label histomorphometry. Bone formation rates from the old rats were compared with results from adult (9-month-old) rats that we reported earlier.(4) Bone formation on the periosteal surface of the old rats was predominantly woven-fibered. Periosteal bone formation was observed in a lower percentage of the old rats compared with the younger adult rats for applied loads of 40 N and greater (59% old, 100% adult). However, in the old rats that formed woven bone there were no significant differences in woven bone area (p=0.1) or surface (p=0.24) compared with younger adults. Therefore, the periosteum of old rats had a higher threshold for activation by mechanical loading, but after activation occurred, the cells had the same capacity to form woven bone as younger adult animals. On the endocortical surface, relative bone formation rates in old rats showed a marginal (p=0.06) increase in response to an applied load of 64 N but was not increased at lower loads. The relative bone formation rate in the old rats was over 16-fold less than that reported for the younger adult rats at an applied load of 64 N and the relative bone forming surface in old rats in this study was 5-fold less than it was younger rats under similar loading conditions. In the younger adult rats, a mechanical threshold for lamellar bone formation of 1050 microstrain was calculated for the endocortical bone surface. The old rats required over 1700 microstrain on the endocortical surface before bone formation was increased. The data suggest that both the periosteal and endocortical surfaces of the tibiae of older rats are less responsive to mechanical stimuli.

Type 1-like helper T cell lines responsive to autologous peripheral blood monocytes established from two patients with sarcoidosis

In the present study, T cell lines, designated TU/BAL and KC/LN, were established from bronchoalveolar lavage (BAL) fluid and an affected lymph node, respectively, obtained from patients with active sarcoidosis by cultivating in the presence of IL-2. These cell lines produced IL-2 and proliferated by stimulation with the patient's own peripheral blood mononuclear cells treated with mitomycin C, while three other T cell lines established from ConA-stimulated BAL cells of patients with non-sarcoid lung diseases did not show any proliferative responses. The proliferation was mediated by IL-2, because anti-IL-2R alpha-chain monoclonal antibody (mAb) inhibited this response in a dose-dependent fashion. The adherent cell was a main stimulator of the proliferation. Both CD4 and HLA-DR appeared to be involved, because mAbs against these molecules inhibited this response. These results suggest that T cells obtained from sarcoid patients respond to a certain unknown antigen associated with HLA-DR or some self antigen expressed on the monocytes. Furthermore, both TU/BAL and KN/LN represented a profile of Th1-like cells: they secreted IL-2 and IFN-gamma, but not IL-4, IL-5 and IL-6, when stimulated with PHA in the presence or absence of 12-O-tetradecanoylphorbol-13-acetate. Thus, Th1-like cells activated by some unknown antigen(s) might play roles in the pathogenesis of sarcoidosis.

Mechanotransduction in bone: role of strain rate

Bone tissue can detect and respond to its mechanical environment, but there is no consensus for how bone cells detect mechanical loads. Some think that cells sense tissue deformation (strain) and respond when strain is abnormally high. However, strains in bone tissue are usually very small, and it is questionable whether bone cells are sensitive enough to detect them. Another theory suggests that mechanical loads are coupled to the bone cells by stress-generated fluid flow within the bone tissue, which is dependent on the rate of change of bone strain. We applied bending loads to the tibiae of adult rats to create equivalent peak strains in the bone tissue but with varied rates of strain. Bone formation was significantly increased in the two experimental groups when the highest strain rates were compared with lower strain rates (P < 0.01), and the amount of new bone formation was directly proportional to the rate of strain in the bone tissue. These results suggest that relatively large strains alone are not sufficient to activate bone cells. High strain rates and possibly stress-generated fluid flow are required to stimulate new bone formation.

[Serodiagnosis of Legionella pneumonia--data of our laboratory in the recent 3 years]

We had examined antibody titers against Legionella spp. of patients' sera which were mainly sent from other hospitals, performed with the indirect fluorescent antibody (IFA) method. The clinical status of the cases diagnosed as Legionella pneumonia serologically, were also studied. Out of 105 cases with clinically suspected Legionella pneumonia, 15 cases (14.3%) were seropositive. In 9 out of the 15 cases (60.0%) were caused by Legionella pneumophila serogroup 1. Clinical outline of these 15 cases did not contradict those reported in the literature, and erythromycin was effective in many cases. Significant rises (more than four times) of the titer were observed 3 to 4 weeks after onset in most of cases. We would like to emphasize that this should be performed serodiagnosis of Legionella pneumonia.

[Pulmonary nocardiosis concurrent with Pneumocystis carinii pneumonia in a case of smoldering adult T-cell leukemia]

A 76-year-old man, with concomitant pulmonary nocardiosis and Pneumocystis carinii (PC) pneumonia, is described. He suffered from smoldering type adult T-cell leukemia and strongyloidiasis. Chest X-rays showed bilateral infiltrative shadows. Nocardia asteroides was isolated from sputum and bronchofiberscopic aspirates. PC was not detected, however, despite the chest X-ray raising the suspicion of PC pneumonia. Since PC antigen was detected by immunoelectrophoresis in the absence of other clinical or histologic data, we diagnosed a latent PC infection. He improved with the use of cefuzonam and ST compounds, but experienced recurrence five months after discharge. N. asteroides and PC were detected from sputum on the second admission. As multiple concurrent infections with opportunistic organisms are not uncommon in immunocompromised hosts, we must maintain a high index of suspicion for opportunistic infection in cases such as this one.

Postmitotic osteoclast precursors are mononuclear cells which express macrophage-associated phenotypes

We previously demonstrated that osteoclast-like multinucleated cells were formed within 6 days in cocultures of mouse osteoblastic cells and spleen cells in response to 1 alpha,25-dihydroxyvitamin D3[1 alpha,25(OH)2D3] which was added together with hydroxyurea on Days 4-6 (final 2 days of the 6-day coculture period). Using this coculture system, chronological changes of macrophage-associated phenotypes such as nonspecific esterase (NSE) and antigens to Mac-1, Mac-2, and F4/80 were examined in postmitotic osteoclast precursors during differentiation into osteoclasts induced by 1 alpha,25(OH)2D3 (10 nM) added on Day 4. Osteoclast differentiation was assessed by examining expression of calcitonin receptors (CTRs) by autoradiography using 125I-labeled salmon CT. CTRs were first detected on small mononuclear cells within 12 hr after adding 1 alpha,25(OH)2D3. The number of CTR-positive mononuclear cells attained a maximum at 24 hr and decreased thereafter. CTR-positive multinucleated cells were first observed at 24 hr and reached a maximum population at 48 hr. All CTR-positive cells showed tartrate-resistant acid phosphatase activity (a marker enzyme of osteoclasts). Most of the CTR-positive mononuclear cells which appeared at 12 hr were positive for NSE and antigens to Mac-1 and Mac-2, but negative for F4/80 antigen. The proportion of CTR-positive cells expressing NSE and Mac-1 to total CTR-positive mononuclear cells decreased time dependently. Like authentic osteoclasts, CTR-positive multinucleated cells were negative for NSE and antigens to Mac-1 and F4/80, but positive for Mac-2. These results indicate that postmitotic osteoclast precursors are mononuclear phagocytes with macrophage-associated phenotypes, some of which disappear rapidly during their differentiation into osteoclasts.

The role of calcitonin gene-related peptide (CGRP) in macrophages: the presence of functional receptors and effects on proliferation and differentiation into osteoclast-like cells

It has been shown that both calcitonin gene-related peptide (CGRP) and amylin bind weakly to calcitonin (CT) receptors in osteoclast-like cells formed in vitro and inhibit bone resorption by a cAMP-dependent mechanism. Osteoclasts are thought to be derived from cells of the monocyte macrophage lineage, in which CGRP, but not CT, induces cAMP production. In this study, we determined the presence of functional receptors for CGRP in mouse alveolar macrophages and the effects of this peptide on proliferation and osteoclastic differentiation in mouse alveolar and bone marrow-derived macrophages. Human CT did not stimulate cAMP production in macrophages. Human CGRP stimulated cAMP production in mouse alveolar macrophages and bone marrow-derived macrophages dose-dependently. Human amylin, which has 43% homology with human CGRP, also stimulated these macrophages to produce cAMP, but only at a 100-fold higher concentration. The increment in cAMP production induced by human CGRP and amylin was abolished by the addition of human CGRP(8-37), a selective antagonist for CGRP receptors. Specific binding of [125I]human CGRP to alveolar macrophages was detected (dissociation constant, 2.5 x 10(-8) M; binding sites, 1.4 x 10(4)/cell). Amylin, but not CT, displaced the bound [125I]human CGRP from alveolar macrophages, but at a 100-fold higher concentration. No specific binding of [125I]human CT and [125I]human amylin to alveolar macrophages could be detected. Pretreatment with human CGRP for 24 h dose-dependently suppressed DNA synthesis in alveolar macrophages induced by granulocyte-macrophage colony-stimulating factor (GM-CSF). CGRP also suppressed the number of macrophage colonies formed from bone marrow cells induced by macrophage colony-stimulating factor (M-CSF).(ABSTRACT TRUNCATED AT 250 WORDS)

Mechanism of action of amylin in bone

Amylin is a 37 amino acid peptide produced mainly by beta-cells of the endocrine pancreas. Human amylin has 43% homology with human calcitonin gene-related peptide (CGRP) and 13% homology with human calcitonin (CT). Amylin and CGRP have been reported to have CT-like hypocalcemic activity in vivo. To investigate the role of amylin in bone, we examined the mechanisms of action of human amylin, CGRP, and CT in osteoclasts and osteoblasts. Both human amylin and CGRP inhibited 1 alpha,25-dihydroxyvitamin D3 [1 alpha,25(OH)2D3]- induced bone resorption in an organ culture system, and the potencies of the two peptides were similarly approximately 60-fold lower than that of human CT. Using a recently developed procedure for preparing large numbers of osteoclast-like multinucleated cells (MNCs) formed in co-cultures of mouse osteoblasts and bone marrow cells in the presence of 1 alpha,25(OH)2D3, we found that both human amylin and CGRP stimulated cAMP production in osteoclast-like MNCs, but only at 60-fold higher concentrations than human CT. Specific binding of [125I]-human CT to osteoclast-like MNCs was detected (dissociation constant, 3 x 10(-8) M; binding sites, 3 x 10(7) per cell). To displace the bound [125I]-human CT from osteoclast-like MNCs, about 170-fold higher concentrations of human amylin and CGRP were required. No specific bindings of [125I]-amylin and [125I]-CGRP to osteoclast-like MNCs could be detected. Human CGRP stimulated cAMP production both in established mouse osteoblast-like cells (KS-4) and in mouse primary osteoblast-like cells. Amylin was a weak agonist for cAMP production in KS-4 cells. The increment in cAMP production induced by CGRP and amylin was abolished by the addition of human CGRP(8-37), a selective antagonist for CGRP receptors. CT did not stimulate cAMP production in KS-4 cells. Amylin, but not CT, displaced the bound [125I]-human CGRP from rat brain membranes. These results indicate that amylin binds not only to CT receptors in osteoclast-like MNCs but also to CGRP receptors in osteoblasts. The relative potencies of these compounds to induce cAMP production was CT greater than amylin not equal to CGRP in osteoclast-like MNCs and CGRP greater amylin much greater than CT in osteoblast-like cells.

[Detection of Legionella pneumophila using a nested polymerase chain reaction]

We evaluated the usefulness of a Nested PCR method for detecting Legionella pneumophila. This method resulted in L. pneumophila specific detection as far as we evaluated. The first and second step PCR achieved the sensitivity as small as 10 pg and 10 fg of the target DNA, respectively. In the detection from Legionella seeded sputa, the method could detect 0.1 cfu/ml of the bacteria, and it took about 12 hours to detect the target DNA. We demonstrated that the Nested PCR method was superior in sensitivity and rapidity for isolation of the bacteria to the conventional using low pH treatment and selective media for Legionella.

[Mechanism of acquired resistance against Legionella--blastogenic responses of murine spleen lymphoid cells following the stimulation with Legionella antigens]

We have tried to characterize the blastogenic responses of murine spleen lymphoid cells from BALB/c mice immunized with Legionella pneumophila serogroup (SG) 1 (Philadelphia 1 strain) and non-treated mice. Lymphoid cells from immunized mice showed stronger blastogenic responses following stimulation with concanavalin A or formalin-treated L. pneumophila SG1 whole cell antigen than those showed by lymphoid cells from non-treated mice. These cells from immunized mice also responded strongly when stimulated in vitro with other SGs of L. pneumophila, while these responded weakly when stimulated with other species of Legionella. Serum antibody titers of immunized mice against each SG of L. pneumophila were examined and the cross reactions were also recognized. However, the relatedness of serum antibody titers and the blastogenic responses against each serogroup of L. pneumophila was small. The epitopes recognized by the cellular immunity might be different in part from those recognized by serum antibodies, and investigations should be made on what the cellular immunity recognizes and how it works.

Effect of human urinary colony-stimulating factor on experimental Legionella pneumophila infection in guinea pigs

The effect of human urinary colony-stimulating factor (CSF-HU) on in-vitro phagocytosis of Legionella pneumophila, superoxide anion production and intracellular killing of Legion, pneumophila by guinea pig alveolar macrophages was studied. Alveolar macrophages when incubated with CSF-HU demonstrated enhanced phagocytic activity and superoxide production. The bactericidal activity of treated cells was enhanced when they were afterwards incubated with a low concentration of bacteria, but these cells failed to inhibit bacterial multiplication when they were incubated with bacteria in a 1:10 ratio. In vivo, an increase in the total peripheral leucocyte count in guinea pigs after intraperitoneal injection of CSF-HU occurred and this was accompanied by an increase in granulocyte and monocyte counts. A comparison of treatment of experimental Legion, pneumophila pneumonia with CSF-HU alone, ceftazidime alone and a combination revealed lower mortality rates in the group receiving combination therapy. These data suggest a possible function for CSF-HU of enhancing antibiotic therapy in Legionnaires' disease.