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Biomedical subjects

M J Malone

Publications and source records attributed to M J Malone.

At least 19 recordsLinked to original sources
PubMed2001

Induction of macrophage matrix metalloproteinase biosynthesis by surfactant protein D.

Recent studies strongly suggest that surfactant protein D (SP-D) plays important roles in pulmonary host defense and the regulation of immune and inflammatory reactions in the lung. Although SP-D can bind to alveolar macrophages and can elicit their chemotaxis, relatively little is known about the direct cellular consequences of SP-D on the function of these cells. Because matrix metalloproteinases (MMPs) are synthesized in increased amounts in response to various proinflammatory stimuli, we investigated the capacity of SP-D to modulate the production of MMPs by freshly isolated human alveolar macrophages. Unexpectedly we found that recombinant rat SP-D dodecamers selectively induce the biosynthesis of collagenase-1 (MMP-1), stromelysin (MMP-3), and macrophage elastase (MMP-12) without significantly increasing the production of tumor necrosis factor alpha and interleukin-1beta. SP-D did not alter the production of these MMPs by fibroblasts. Phosphatidylinositol, a surfactant-associated ligand that interacts with the carboxyl-terminal neck and carbohydrate recognition domains of SP-D, inhibited the SP-D-dependent increase in MMP biosynthesis. A trimeric, recombinant protein consisting of only the neck and carbohydrate recognition domain did not augment metalloproteinase production, suggesting that the stimulatory effect on MMP production depends on an appropriate spatial presentation of trimeric lectin domains. Although SP-D dodecamers can selectively augment metalloproteinase activity in vitro, this effect may be competitively inhibited by tissue inhibitors of metalloproteinases or surfactant-associated ligands in vivo.

Animals↗
PubMed1999

Complex renal reconstruction.

This article provides a complete review of current renal reconstructive techniques. The techniques described include partial nephrectomy, intrasinusal surgery, anatrophic nephrolithotomy, nonvascular bench procedures with autotransplantation, and allograft partial nephrectomy in renal transplantation. A detailed discussion on renovascular and collecting system anatomy and current indications for these procedures is presented.

Humans↗
PubMed1998

Endoscopic injection of glutaraldehyde cross-linked collagen for efferent limb incompetence in the Indiana reservoir.

PURPOSE: We determined the clinical applicability, safety and efficacy of endoscopically injected glutaraldehyde cross-linked collagen for the treatment of efferent limb incompetence in the incontinent Indiana urinary reservoir. MATERIALS AND METHODS: Six patients were diagnosed with incompetence of the efferent limb of the Indiana reservoir by video urodynamics. Glutaraldehyde cross-linked collagen was injected through the efferent limb at the level of the ileocecal valve. Outcome was assessed by evaluation of dryness and pouchograms. RESULTS: With a mean followup time of 26 months (range 6 to 36) after the last injection 5 of the 6 patients were cured. The remaining patient, although improved, had a small capacity and subsequently underwent ileal patch augmentation. No patient failed to improve. The mean volume of collagen was 16 ml. (range, 5 to 26). Reservoir volume increased from 150 to 400 ml. CONCLUSIONS: The use of glutaraldehyde cross-linked collagen in the treatment of the incontinent Indiana reservoir is safe and effective.

Adult↗
PubMed1997

Carcinogenesis. The fate of intestinal segments used in urinary reconstruction.

The actual mechanism for risk of developing cancer in intestinal segments used for urinary diversion remains uncertain. The clinical and laboratory experiences are reviewed in this article. The pathogenesis is multifaceted, involving initiators and promoters of carcinogenesis. Molecular genetic technology may provide the key to decoding the mechanisms involved.

Humans↗
PubMed1997

Stomal construction, complications, and reconstruction.

This article reviews stomal complications and their management. To accomplish this goal, the authors review techniques used for planning and creating the stomas for both continent reservoirs and incontinent conduits.

Humans↗
PubMed1997

Use of small and large bowel in renal transplantation.

The continued success of renal transplantation has provided a higher quality of life for properly selected patients with ESRD. It is also a much more cost-effective and efficient treatment of ESRD compared with chronic dialysis. Innovative urologic reconstructive surgery using enteric segments for both continent and incontinent urinary diversions has permitted this therapeutic modality to be offered to the recipient with lower urinary tract disease not previously amenable to renal transplantation. These same reconstructive techniques using ileal segments have also permitted preservation of renal allografts with previously nonreconstructable renal pelvic or ureteral disease.

Humans↗
PubMed1997

Individual risk and social risk as interacting determinants of victimization in the peer group.

This study evaluated the hypothesis that the behavior problems that place children at risk for victimization by peers are associated with victimization primarily when children are also at social risk for victimization. Social risk was defined as lacking supportive friends or as being rejected by the peer group. Participants were 229 boys and girls in the 3rd through 7th grades (M age = 11 years 2 months). As predicted, behavior problems (internalizing problems, externalizing problems, and physical weakness) were more strongly related to victimization when children had few friends, had friends who were incapable of fulfilling a protective function (e.g., were physically weak), or were rejected by peers than when children had more friends, had friends capable of defending them, or were better liked by peers. Results illustrate the principle that individual risk variables depend on social context for expression.

Child↗
PubMed1994

Primary skeletal metastasis of a nonseminomatous germ cell tumor.

Bony metastasis is common in patients with germ cell tumor of the testicle; however, it is usually seen late in the disease process and is associated with lymph node or other visceral involvement. We present a case of isolated bony metastasis in a patient with a nonseminomatous germ cell tumor of the testis and normal retroperitoneal lymph nodes as determined by surgical resection.

Adult↗
PubMed1993

Computerized tomographic appearance of hernias of the bladder.

Herniation of the bladder is not uncommon and it can occur with any type of hernia in the groin. Most bladder hernias are discovered unexpectedly during herniorrhaphy, and serious complications can result from intraoperative injury to the bladder. The appearance of hernias on excretory urography and cystography has been described extensively but experience with computerized tomography (CT) has been limited. We describe the appearance of 8 bladder hernias on CT: 2 incisional, 2 femoral, 3 small direct inguinal, and 1 massive direct inguinal hernia with bladder necrosis and perforation. Appearance on CT is characteristic, and this modality may be useful for preoperative evaluation.

Aged↗
PubMed1990

How not to practice geriatrics.

They're slow, they're hard-of-hearing, they don't get better--elderly patients can be a pain in the practice. Here's how to keep them away.

Aged↗
PubMed1989

Post-mortem stability of membrane-associated sialidase activity in brain.

The post-mortem changes in membrane-associated sialidase (N-acetylneuraminosyl glycohydrolase, EC 3.2.1.18) were examined in rat brain obtained and stored in a manner which paralleled neuropathological handling of human brains. When whole brains were held at 4 degrees C in covered containers for varying periods of time (0.67 h), sialidase activity toward endogenous membrane substrate was elevated. This elevated activity was maximal at 8 h of storage and decreased thereafter. The apparent decrease in enzyme activation from 8 to 67 h of storage was not due to a reduction of activity, but was the result of depletion of endogenous membrane substrate, since activity toward exogenous ganglioside remained elevated. The changes were due to whole brain storage at 4 degrees C, and not a result of being stored at -80 degrees C. The post-mortem activation of sialidase was not due to the expression of a new form of the enzyme, since it displayed characteristics similar to those reported previously: (a) membrane gangliosides being the preferred native substrate, and (b) ganglioside GM1 and lactosylceramide being the major hydrolytic products. The results underscore the importance of post-mortem storage conditions when analyzing complex carbohydrates of brain.

Animals↗
PubMed1989

Preoperative and surgical management of pheochromocytoma.

The clinical awareness of the various presentations of pheochromocytoma, along with newer monitoring and anesthetic techniques, has enabled early diagnosis and less fluctuation of blood pressure during operation. The use of meticulous surgical technique through the various incisions outlined in this article has made the excision of pheochromocytoma an expeditious operation and the accompanying hypertension surgically curable. Thus, pheochromocytoma is less likely to be a fatal lesion.

Adrenal Gland Neoplasms↗
PubMed1988

Complications of ureteroscopy.

Ureteroscopy with the rigid instrument is now an integral part of the endourologic armamentarium for the management of patients with ureteral calculi. Our experience demonstrates that ureteroscopy can be a safe, efficacious, and less invasive modality. Morbidity will be lowered with proper patient selection, meticulous attention to technique, and use of the proper equipment. Prevention is the best way to avoid serious complications of ureteroscopy. The following guidelines are recommended: Ureteroscopy should be used primarily for patients with distal ureteral calculi. A guidewire should be in place at all times during ureteroscopy. Fragmentation devices should be available. No forceful manipulations should be undertaken during either introduction of the instrument or manipulation of the calculus. When access or manipulation is difficult, a stent should be placed in the ureter for ureteroscopy at a later date. When perforation occurs, a stent should be placed in the ureter and the injured dry unstented ureter complex avoided. Alternative endourologic modalities should be used when appropriate. When practicing urologists are aware of the indications, potentials, and limitations, ureteroscopy and other endourologic methods will permit safe successful treatment of most patients with ureteral calculi.

Adult↗
PubMed1987

Transcriptional control of the inducible nitrate reductase isoform from soybeans.

The activity of the pH 7.5 NADH-linked nitrate reductase isoform from soybean seedlings is termed inducible. Activity is present only in the leaves of seedlings which have been supplied nitrate. A cDNA clone that encoded part of the mRNA for squash nitrate reductase hybridized specifically with mRNA for this inducible nitrate reductase isoform. Nitrate induction resulted in an increase in the steady-state levels of mRNA for this isoform after 24 hours, while the addition of glutamine to the nitrate diminished steady-steady state levels of this mRNA.

Enzyme Induction↗
PubMed1986

Renal angiomyolipoma: 6 case reports and literature review.

We report 6 cases of renal angiomyolipomas and review the pertinent literature concerning this disease. One case involved the rare association of tuberous sclerosis and pregnancy. Another patient without tuberous sclerosis had renal cell carcinoma and later suffered a contralateral angiomyolipoma. The pathological conditions of renal angiomyolipomas with and without tuberous sclerosis are discussed. Since angiomyolipomas present with multiple clinical similarities to renal cell carcinoma, the primary task for the clinician is to differentiate this hamartoma from carcinoma. The distinguishing characteristics and the clinical management of renal angiomyolipomas are discussed.

Adult↗