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J Salo

Publications and source records attributed to J Salo.

At least 37 records · Page 2Linked to original sources
PubMed2000

Unified description of nondiffracting X and Y waves

A unified spectral and temporal representation is introduced for nondiffracting waves. We consider a set of elementary broadband X waves that spans the commonly considered nondiffracting wave solutions. These basis X waves have a simple spectral representation that leads to expressions in closed algebraic form or, alternatively, in terms of hypergeometric functions. The span of the X waves is also closed with respect to all spatial and temporal derivatives and, consequently, they can be used to compose different types of waves with complex spectral and spatial properties. The unified description of Bessel-based nondiffracting waves is further extended to include singular Neumann and Hankel waves, or Y waves. We also discuss connections between the different known nondiffracting wave solutions, and their relations to the present unified approach.

Journal Article↗
PubMed1999

High-dose methotrexate in combination with interferons in the treatment of malignant pleural mesothelioma.

Twenty six patients with pleural mesothelioma of UICC stage I-IV excluding M1 disease (46% of whom had stage I disease and 38% stage III disease) were treated intravenously with high dose MTX (3 g) and calcium folinate rescue three times at intervals of 2 weeks and three times at intervals of 3 weeks. Natural interferon (IFN)-alpha (3 MIU days 2-10) and recombinant IFN-gamma1b (50 microg m(-2) on days 2, 6 and 10) were injected subcutaneously after each MTX dose. At the end of MTX treatment the IFNs were continued as maintenance therapy until disease progression. Seven partial responses were observed among 24 patients evaluable for response (response rate 29%, 95% confidence interval 13-51%). Median duration of response was 10 months (range 3-24 months). Median survival was 17 months and 1-year and 2-year survival rates 62% and 31% respectively. The toxicity of the chemo-immunotherapy was acceptable. Treatment was stopped in one patient who developed grade IV neurological toxicity. MTX dose reductions were rare (two patients with grade 1-2 renal toxicity). The combination of high dose MTX and IFN-alpha and IFN-gamma is active against malignant pleural mesothelioma and well-tolerated. The survival rates are encouraging.

Adolescent↗
PubMed1999

Surgery for lung cancer in the elderly.

In order to assess the appropriateness of lung cancer surgery in the elderly and determine optimal subjects and resection procedure, 75 patients operated on in 1976-1996 at age > or =75 years (including 13 > or =80) were followed up. The operations included limited resection (8), lobectomy (47), bilobectomy (10) and pneumonectomy (10) and were judged to be radical in 59 cases (79%). Perioperative mortality was 9% and morbidity 29%, including 21% major complications. Cumulative 5-year survival was 32%, in stages IA-IIB 27-41%, and cancer-related survival 61-79%. Mortality did not differ significantly between resection types, but morbidity did. Nor did mortality, morbidity or survival differ between the age groups 75-79 and > or =80 years. In stage I cancer there was no significant difference in survival or cancer-related survival after lobectomy vs limited resection. We conclude that age, even >80 years, is not incompatible with curative resection. Lobectomy is the treatment of choice, but a less radical resection may be advisable if there is comorbidity. If more extensive resection is performed, the individual surgical risk must be weighed against the potential long-term benefit.

Age Factors↗
PubMed1999

Life-threatening Mycoplasma hominis mediastinitis.

Mycoplasma hominis infections are easily missed because conventional methods for bacterial detection may fail. Here, 8 cases of septic mediastinitis due to M. hominis are reported and reviewed in the context of previously reported cases of mediastinitis, sternum wound infection, pleuritis, or pericarditis caused by M. hominis. All 8 patients had a predisposing initial condition related to poor cardiorespiratory function, aspiration, or complications related to coronary artery surgery or other thoracic surgeries. Mediastinitis was associated with purulent pleural effusion and acute septic symptoms requiring inotropic medication and ventilatory support. Later, the patients had a tendency for indolent chronic courses with pleuritis, pericarditis, or open sternal wounds that lasted for several months. M. hominis infections may also present as mild sternum wound infection or as chronic local pericarditis or pleuritis without septic mediastinitis. Treatment includes surgical drainage and debridement. Antibiotics effective against M. hominis should be considered when treating mediastinitis of unknown etiology.

Adult↗
PubMed1999

The role of parenteral polyestradiol phosphate in the treatment of advanced prostatic cancer on the threshold of the new millennium.

Orchiectomy and estrogens have been used for over 50 years in the treatment of advanced prostatic cancer. Although orchiectomy is a simple procedure, it may cause psychological stress. Oral estrogen therapy is as effective as orchiectomy in terms of cancer inhibitory effect, but its acceptance as primary hormonal treatment is overshadowed by an increased risk of cardiovascular complications. Parenteral estrogen, polyestradiol phosphate (PEP), is effective, but also associated with cardiovascular complications, although to a lesser extent. During the last 20 years, well tolerated luteinizing hormone releasing hormone (LHRH) analogues have been replacing orchiectomy and estrogens. Efforts have been made to increase the efficacy of the treatment by adding antiandrogens to LHRH analogues and also to orchiectomy (combined androgen blockade, CAB). However, the efficacy of LHRH analogues and CAB has not proved to be superior to that of simple orchiectomy and, moreover, they are expensive treatment modalities. Orchiectomy and LHRH analogues are associated with negative effects on bone mass and may cause osteoporosis, whereas PEP treatment has an opposite effect. Parenteral polyestradiol phosphate is still a cheap potential treatment for advanced prostatic cancer, but further studies should be conducted to establish its future role, e.g. combining acetylsalicylic acid to prevent cardiovascular complications.

Androgen Antagonists↗
PubMed1999

Surgical therapy of hepatic colorectal metastasis.

The liver is a common site of metastases from colorectal cancer. The data are convincing that liver resection is a safe and effective therapy for such metastatic disease. Even extensive resections can be performed with a less than 5% mortality rate at major centers and a 5-year survival rate of 30% to 40%. This review examines factors important for patient selection for liver resection and proposes a prognostic scoring system that may help in patient selection. For unresectable disease, many methods for ablating tumors are now available that will likely prove to be useful adjuncts to current treatment.

Colorectal Neoplasms↗
PubMed1999

Studies of host response to orthopedic implants and biomaterials.

The use of implanted biomaterials in orthopedic surgery has increased rapidly during the past two decades. Total joint replacement of the hip or knee joint has become common treatment; at the same time, an increasing number of fractures are treated with osteosynthesis. The original Charnley low-friction arthroplasty of the hip is still widely used and gives in large series excellent results. Aseptic loosening of this arthroplasty has been thought to be due to wear debris of the methylmethacrylate used for fixation of the implants, or to debris generated from wear of the polyethylene socket. To date, many different materials have been tried in order to reduce wear and generation of macrophage irritating submicron sized particles, or to provide more biocompatible components. However, trials to improve the methylmethacrylate cement or to invent better polyethylenes have often failed. Diamond coating of the metallic components seems promising: there is less wear and diamond is very biocompatible in bulk and small particulate form. Biodegradable implants have also been found useful in treating fractures. Bioactive bioabsorbable materials may also make possible a tissue engineering approach and can be used as carriers for selected drugs and cytokines. Because many promising materials and designs have failed in clinical use, extensive theoretical and experimental testing is mandatory before introducing new materials and implants in a clinical setting.

Biocompatible Materials↗
PubMed1998

The clinical importance of magnetic resonance imaging versus computed tomography in malignant pleural mesothelioma.

There is no standard therapy for malignant pleural mesothelioma (MPM), but recent reports have shown that extensive surgery combined with chemo- and radiotherapy prolongs the survival of selected patients with early stage disease. This emphasises the need for accurate staging procedures at diagnosis and reliable imaging methods to assess response to treatment. Computed tomography (CT) of the chest has been the standard imaging method for these purposes for the last decade, but it is limited in its ability to demonstrate accurately the platelike growth pattern of MPM within the thorax due to the partial volume effect on curved surfaces. In order to define the value of magnetic resonance imaging (MRI) in the imaging of MPM, we have compared the findings from 26 parallel paired CT and MRI scans of mesothelioma patients at various stages of the disease. MRI showed tumour spread into the interlobar fissures, tumour invasion of the diaphragm and through the diaphragm, and invasion of bony structures better than CT. Invasion of the chest wall and mediastinal soft tissue and tumour growth into the lung parenchyma were equally well seen on both imaging methods. CT was better for detecting the inactive pleural calcifications. MRI is a sensitive detector of the characteristic growth pattern and extension of MPM and we recommend its use more widely for the clinical management of MPM especially when evaluating tumour resectability and in research protocols when an accurate evaluation of disease extent is essential.

Adult↗
PubMed1998

Estrogen enhances differentiation of osteoblasts in mouse bone marrow culture.

The effects of estrogen on bone are possibly mediated by several cell types. In the present study, the effect of 17beta-estradiol (E2) on osteoblast-like cells was investigated by using mouse bone marrow cultures. Bone marrow cells were harvested from the shafts of femurs of 10-week-old NMRI mice and cultured. On day 6, confluent primary cultures were trypsinized and subcultured. Under the conditions used (Keila, S., Pitaru, S., Grosskopf, A., and Wernreb, M. Bone marrow from mechanically unloaded rat bones expresses reduced osteogenic capacity in vitro. J Bone Miner Res 9:321-327; 1994), the bone marrow cultures showed differentiation towards the osteoblastic phenotype. This was demonstrated by the appearance of osteoblastic markers such as alpha1(I) collagen (COL1), alkaline phosphatase (ALP), osteocalcin (OCN), osteopontin (OP), and transforming growth factor-beta1 (TGFbeta1), which were detected by using reverse transcriptase polymerase chain reaction (RT-PCR). Bone nodule formation, including deposition of collagen fibers and matrix mineralization, was also studied at several time points of the 3-week culture period. The effect of E2 on the appearance of osteoblastic markers was studied by incubating cultures in the presence or absence of the hormone. The messenger ribonucleic acid (mRNA) for the estrogen receptor (ER) was found to be expressed at all time points as demonstrated by RT-PCR. When grown with E2, the rate of cell proliferation was increased in the early phase of cultures, but not after day 6. The addition of E2 in subcultures resulted in an increase of levels of mRNA for COL1, ALP, OCN, OP, and TGF-beta1. ALP activity was also increased. Bone nodule formation, as well as calcium contents, were significantly increased in the cultures grown in the presence of E2. All E2 concentrations used (0.01-10 nmol/L) were effective but the maximum response was obtained with 0.1 nmol/L E2. Addition of the antiestrogen ICI 182,780 abolished the E2-induced stimulation of proliferation and later an increase in ALP activity. Addition of ICI 182,780 without the hormone did not cause any changes when compared to control cultures. In conclusion, our results demonstrate that E2 stimulates sequential differentiation of osteoblasts and increases deposition and mineralization of matrix in mouse bone marrow cultures in an estrogen receptor-dependent manner.

Alkaline Phosphatase↗
PubMed1998

Macrophage activation results in bone resorption.

Monocytes or macrophages from important accessory cells in the regulation of bone metabolism and destruction. Cells of the mononuclear phagocyte lineage form the precursor cells of the osteoclasts. Soluble products produced by activated macrophages regulate progenitor cell proliferation, recruitment, differentiation, and activity of osteoblasts and osteoclasts. After osteoclasts are removed from the resorption site, macrophages process bone surfaces and create a cement line before osteoblasts enter to form new bone. Although osteolysis associated with normal bone remodeling is seen as an osteoclast driven process, it may be that in chronic inflammation macrophage activation and vascular derangements lead to low pH, local bone demineralization (acid attack), and H+ mediated stimulation of the primary afferent nociceptive nerve fibers (bone pain). Osteoclasts are not able to attach to demineralized bone or to osteoid surfaces. However, if macrophages degrade the demineralized organic bone matrix, chemotactic factors and attachment sites for osteoclasts are produced. In such a scenario, the osteoclast-osteoblast mediated activation, resorption, and formation cycle would be secondarily activated. Such events may play a role in the most common orthopaedic problem related to macrophage activation, aseptic loosening of orthopaedic joint implants, which is secondary to a chronic foreign body reaction and to micromovement.

Bone Resorption↗
PubMed1998

Laparoscopic Nissen fundoplication: a prospective analysis of 200 consecutive patients.

Nissen fundoplication is now the most common antireflux operation for gastroesophageal reflux disease. This study is a report on the laparoscopically performed floppy Nissen procedure. Two hundred consecutive patients were analyzed (84 women, 116 men, mean age 49 years, mean duration of symptoms 5 years) after laparoscopic Nissen fundoplication between 1992 and 1996. The main indications for surgery were daily heartburn, retrosternal pain, and regurgitation demanding continuous medical therapy. Eight patients (4%) had esophageal stricture, and 21 (11%) had Barrett's esophagus with intestinal metaplasia. All patients underwent upper gastrointestinal endoscopy, 24-h esophageal pH monitoring, and esophageal manometry before and 3 months after the operation. In addition, a questionnaire was completed an average of 2.2 years (range 1.0-4.6) after the operation. The results of the study were as follows: mortality was zero, and the morbidity rate was 5%. The mean hospital stay was 3.8 +/- 2.8 days, and sick leave was 14.3 +/- 10.4 days. Postoperatively, esophagitis was healed or significantly improved in all but 4 patients (98%), and 24-h pH and lower esophageal sphincter pressure were normal. After 2 years, 87% of the patients had Visick scores of I-II. It is concluded that laparoscopic floppy Nissen fundoplication provides an efficient and safe alternative for surgical treatment of gastroesophageal reflux disease.

Adult↗
PubMed1997

Time-resolved fluorescence imaging in islet cell autoantibody quantitation.

The prodromal period of insulin-dependent diabetes mellitus (IDDM) is characterized by circulating islet cell autoantibodies (ICA) and other beta cell specific autoantibodies. Despite biochemical characterization of the major beta cell autoantigens insulin, glutamic acid decarboxylase and protein tyrosine phosphatase and development of the respective antibody assays, ICA has remained the standard in IDDM prediction. Conventional ICA quantitation using classic fluorochromes is prone to errors since fluorescence intensity is estimated subjectively using the human eye, which is also unable to differentiate specific signals from non-specific signals and autofluorescence. Using Eu(3+)-chelate labelled anti-human polyclonal IgG (decay time 1000 microseconds) as the secondary antibody in time-resolved fluorescence imaging (TRFI), the chelate and autofluorescence signals (typical decay time < 100 ns) are fully separated. The image is recorded using an optically gated cooled digital CCD camera. The specificity of the ICA signal is further improved by interactive analysis of the image. Signal detection is objective, the signal-to-background ratio improves, and ICA quantitation is possible using undiluted serum. Of 57 consecutive new-onset IDDM patients, 55 (96.5%) were ICA positive in the new assay while 51 (89.5%) were positive in the conventional assay suggesting that the sensitivity of TRFI exceeds that of the IAA, GAD65 and IA-2 autoantibody assays combined. For later comparisons, the stained slides may be stored in the light for years without any decrease in specific fluorescence.

Adolescent↗
PubMed1997

Removal of osteoclast bone resorption products by transcytosis.

Osteoclasts are multinucleated cells responsible for bone resorption. During the resorption cycle, osteoclasts undergo dramatic changes in their polarity, and resorbing cells reveal four functionally and structurally different membrane domains. Bone degradation products, both organic and inorganic, were endocytosed from the ruffled border membrane. They were then found to be transported in vesicles through the cell to the plasma membrane domain, located in the middle of the basal membrane, where they were liberated into the extracellular space. These results explain how resorbing osteoclasts can simultaneously remove large amounts of matrix degradation products and penetrate into bone.

Actins↗
PubMed1997

Computer analysis of living cells: movements of the chromatoid body in early spermatids compared with its ultrastructure in snap-frozen preparations.

Quantitative analyses of cytoplasmic and nuclear organelle movements in living interphase cells at defined stages of differentiation are few. By phase contrast videomicroscopy and digital imaging techniques, we have traced the path of the chromatoid body (CB) and analysed its rapidly changing positions in relation to the nuclear envelope, Golgi complex and nuclear pale chromatin areas in living early spermatids of the rat. The CB had intimate interactions with the nuclear envelope and moved both in parallel and perpendicular fashion in relation to it. It had successive short contacts with the Golgi complex and nuclear pale chromatin areas. It was also seen to scan between two pale chromatin areas and it had pinocytosis-like transient engulfments during interactions with the pale chromatin. In ultrastructural analysis of snap-frozen preparations, the CB had a large contact area with the nuclear envelope with several intermediate organelles that may be involved in nucleocytoplasmic material transport. It is evident that quantitative image analysis of living cells is a powerful guide for ultrastructural analyses. The snap-freezing technique gives new possibilities for studies of structures that are sensitive to conventional fixation procedures.

Animals↗
PubMed1997

MRI and CT in blunt renal trauma: an update.

In our experience, MRI is as effective as CT in correctly staging renal injury. The coronal and sagittal slice orientations of MRI are particularly helpful in determining the extent of the renal parenchymal damage. Both methods are accurate in finding perirenal hematomas, assessing the viability of renal fragments, and detecting preexisting renal abnormalities but are relatively inaccurate in visualizing urinary extravasation. Although CT remains the method of choice in radiological staging of renal injury, MRI can complement CT in patients with severe renal injury, preexisting renal abnormality, equivocal CT findings, or when repeated radiological follow-up is required. MRI could replace CT in patients with iodine allergy and be used for initial staging if CT is not available.

Humans↗