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Biomedical subjects

M Bansal

Publications and source records attributed to M Bansal.

At least 109 records · Page 6Linked to original sources
PubMed1988

Quantification of osteopenia in hip fracture patients.

Osteopenia was assessed in 56 consecutive hip fracture patients by using dual photon absorptiometry of the lumbar spine and uninjured, contralateral femoral neck and by performing iliac crest biopsy. Of the 56 patients, 47 were female and 9 were male. The mean age was 78 years. There were 31 femoral neck and 25 intertrochanteric fractures. Two comparison populations were also studied. Population 1 consisted of 269 postmenopausal females older than 60 years of age with no history of fracture who were referred for dual photon absorptiometry of the lumbar spine as screening for osteoporosis. Population 2 included 94 patients with vertebral compression fractures who underwent transilial biopsy to evaluate osteoporosis. All transilial biopsies were assessed with the use of quantitative histomorphometry. Dual photon absorptiometry of the lumbar spine indicated that 76.9% of the hip fracture patients had severe bone loss (less than 1 gm/cm2). Nevertheless, no difference in spinal bone density was found when the hip fracture patients were compared to population 1. No difference in density of the lumbar spine or femoral neck was found in patients in the hip fracture group when intertrochanteric and femoral neck fractures were compared. No difference in histomorphometric measurements of total bone, cortical bone, and cancellous bone volume was noted between the hip fracture patients and population 2. There was no difference noted when the intertrochanteric and femoral neck fracture patients were compared. No evidence of osteomalacia was noted in any group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

The differential diagnosis of geodes.

Lytic lesions close to or at the articular margins are secondary to a wide range of etiologies, including osteoarthritis, rheumatoid arthritis, hemophilic arthropathy, and crystal deposition disease as well as tumor and tumor-like conditions. In many cases the features of these "cysts" are distinctive, and the purpose of this article is to outline the characteristic hallmarks in some of the more frequently encountered arthropathies.

Arthritis, Rheumatoid↗
PubMed1988

Analysis of surface damage in retrieved carbon fiber-reinforced and plain polyethylene tibial components from posterior stabilized total knee replacements.

The performance of carbon fiber-reinforced ultra-high molecular weight polyethylene was compared with that of plain (non-reinforced) polyethylene on the basis of the damage that was observed on the articulating surfaces of retrieved tibial components of total knee prostheses. Established microscopy techniques for subjectively grading the presence and extent of surface damage and the histological structure of the surrounding tissues were used to evaluate twenty-six carbon fiber-reinforced and twenty plain polyethylene components that had been retrieved after an average of twenty-one months of implantation. All of the tibial components were from the same design of total knee replacement. The two groups of patients from whom the components were retrieved did not differ with regard to weight, the length of time that the component had been implanted, the radiographic position and angular alignment of the component, the original diagnosis, or the reason for removal of the component. The amounts and types of damage that were observed did not differ for the two materials. For both materials, the amount of damage was directly related to the length of time that the component had been implanted. The histological appearance of tissues from the area around the component did not differ for the two materials, except for the presence of fragments of carbon fiber in many of the samples from the areas around carbon fiber-reinforced components.

Carbon↗
PubMed1988

Overview of geriatric osteopenic syndromes. Part I: Definition and pathophysiology.

The clinical features of osteoporosis are identified, and their role in distinguishing this disease entity from osteomalacia, osteopenia, endocrinopathies, and marrow-packing disorders is discussed. An update is also offered on the ways in which calcium intake and estrogen levels are implicated in the pathophysiology of bone mass loss.

Aged↗
PubMed1988

Evaluation of benign acetabular lesions with excision through the Ludloff approach.

Six patients with poorly defined chronic hip symptoms (length of time from initial symptoms to definitive diagnoses ranged from four months to three years) were eventually found to have benign lesions in the region of the acetabular fovea. All of these patients had seen multiple physicians including orthopedic surgeons before the definitive diagnosis was made. Four lesions were not visualized on routine roentgenographs. Various imaging modalities were necessary to demonstrate and localize these lesions. Excision through an anteromedial approach (Ludloff) in five cases required minimal dissection, operative time, and blood loss. The approach does not compromise definitive surgery (external or internal hemipelvectomy) in the unlikelihood that the lesion is found to be malignant.

Acetabulum↗
PubMed1988

Metallic wear in failed titanium-alloy total hip replacements. A histological and quantitative analysis.

We conducted extensive histological examination of the tissues that were adjacent to the prosthesis in nine hips that had a failed total arthroplasty. The prostheses were composed of titanium alloy (Ti-6Al-4V) and ultra-high molecular weight polyethylene. The average time that the prosthesis had been in place in the tissue was 33.5 months (range, eleven to fifty-seven months). Seven arthroplasties were revised because of aseptic loosening and two, for infection. In eight hips cement had been used and in one (that had a porous-coated implant for fifty-two months) no cement had been utilized. Intense histiocytic and plasma-cell reaction was noted in the pseudocapsular tissue. There was copious metallic staining of the lining cells. Polyethylene debris and particles of cement with concomitant giant-cell reaction were present in five hips. Atomic absorption spectrophotometry revealed values for titanium of fifty-sic to 3700 micrograms per gram of dry tissue (average, 1047 micrograms per gram; normal, zero microgram per gram), for aluminum of 2.1 to 396 micrograms per gram (average, 115 micrograms per gram; normal, zero micrograms per gram), and for vanadium of 2.9 to 220 micrograms per gram (average, sixty-seven micrograms per gram; normal, 1.2 micrograms per gram). The highest values were found in the hip in which surgical revision was performed at fifty-seven months. The concentrations of the three elements in the soft tissues were similar to those in the metal of the prostheses. The factors to which failure was attributed were: vertical orientation of the acetabular component (five hips), poor cementing technique on the femoral side (three hips), infection (two hips), and separation of a sintered pad made of pure titanium (one hip). A femoral component that is made of titanium alloy can undergo severe wear of the surface and on the stem, where it is loose, with liberation of potentially toxic local concentrations of metal debris into the surrounding tissues. It may contribute to infection and loosening.

Adolescent↗
PubMed1988

Villous lipomatous proliferation of the synovial membrane (lipoma arborescens).

The cases of five patients (7 knees) who had villous lipomatous proliferation of the synovial tissue (lipoma arborescens) are reported. The longest duration of symptoms was thirty years. Six of the seven knees were treated by synovectomy. The length of follow-up ranged from two to eleven years, and six knees were followed for five years or more. The patients who were treated by synovectomy had complete healing of the synovial lesion, but the osteoarthritis tended to progress, especially in patients who had long-standing symptoms. Because of the clinical, macroscopic, and microscopic features of this rare disease, we suggest discarding the name lipoma arborescens, which implies that the lesion is a neoplasm, and using the more descriptive term of villous lipomatous proliferation of the synovial membrane.

Adult↗
PubMed1987

Energetics of left and right handed models of DNA.

It has been shown by model building studies that various right handed and left handed models are compatible with X-ray data of B-DNA and C-DNA. These models are also found to be in good agreement with infrared dichroism data. Detailed potential energy calculations have now been carried out for these models, viz., right and left handed B-DNA and right and left handed C-DNA. It is found that base sugar stacking and interactions involving the phosphate groups are the dominant forces for stabilizing a particular structure. For some sequences, viz., A-A, T-A and C-A, left handed stacking is quite favourable in both B and C structures. But intranucleotide interactions make the left B-DNA unfavourable while the left C-DNA structure is more stable, for all the sequences, than the right C-DNA structure, proposed from fibre data. For the hexanucleoside pentaphosphate fragments the same trend is observed, with the right handed B-DNA being the most stable of the four models studied. However, the left C-DNA structure is only marginally higher in energy, particularly if the shielding effect of the counter ions, on the phosphate group is taken into consideration.

Chemical Phenomena↗
PubMed1986

The purely epithelioid malignant peripheral nerve sheath tumor.

The purely epithelioid malignant peripheral nerve sheath tumor (PNST) is a rare form of PNT possibly first described by McCormack et al. in 1954. This tumor type is distinguishable from the glandular PNT and PNT with differentiated neuroepithelium (medulloepithelioma and neuroepithelioma) and differs from the ordinary epithelioid PNT because of the absence of a spindle cell component typical of malignant PNSTs. The two examples of purely epithelioid malignant PNT we describe arose in the popliteal fossa from the sciatic and tibial nerves of men with no definite evidence of von Recklinghausen's neurofibromatosis. Both tumors were partly mucinous, and so closely mimicked carcinoma and a few non-neurogenic myxoid sarcomas histologically that their final classification depended upon proof of a neural origin.

Adult↗
PubMed1985

Giant cell reparative granuloma in the hand: report of three cases and review of the literature.

Occurrence of giant cell reparative granuloma (GCRG) outside the jaw, skull, or facial bones is unusual. Three recent cases of GCRG occurring in the hand are presented. This lesion appears on radiographs as a lucent, expansile defect in bone, similar in appearance to enchondroma, giant cell tumor of bone, aneurysmal bone cyst, or brown tumor of hyperparathyroidism. Histologically, GCRG is characterized by spindle-shaped, fibroblastic stoma with scattered, small, angulated giant cells and areas of osteoid formation around foci of hemorrhage. Establishing the pathologic diagnosis is frequently difficult. Misdiagnosis occurred in approximately half of the reported cases and in one of our cases. The typical clinical presentation is that of localized pain and swelling. GCRG is not a neoplastic disorder; however, it recurred locally in a third of the reported cases. Recommended treatment for GCRG is thorough removal of the diseased tissues and grafting of autologous bone.

Adolescent↗
PubMed1984

Are metaplasias in colorectal adenomas truly metaplasias?

Five thousand seven hundred seventy-eight adenomas or adenomas containing carcinoma from 3215 patients were examined by routine histologic methods for the presence of epithelial metaplasias. Three forms of epithelial metaplasia were encountered: squamous cell metaplasia (0.44%), Paneth cell metaplasia (0.20%), and melanocytic metaplasia (0.017%). In several instances multiple forms of metaplasia were encountered in the same polyp. In those cases in which the paraffin blocks were available, a Grimelius stain was performed. Grimelius-positive cells were present in 63% of the adenomas containing a metaplastic cell type. All cases with Paneth cell differentiation were immunoreactive for lysozyme; all lesions containing areas of squamous differentiation were immunoreactive for keratin except 2. The histopathologic features of these cases are discussed, and it is concluded that rather than representing a true metaplastic process, Paneth cell, squamous cell, and melanocyte differentiation represent the full range of cellular differentiation that endodermally derived tissues can exhibit, particularly when they undergo neoplastic alterations.

Adenoma↗
PubMed1983

Structure of D-DNA: 8-fold or 7-fold helix?

We have shown that both right- and left-handed uniform helical models (RU and LU models) could be built to give satisfactory agreement with the fibre diffraction data of poly[d(I-C)] in the D-form. Atomic coordinates of these two models are reported in the present work. Molecular transforms of these two models, as well as of the recently published Hoogsteen base-paired 7-fold helical structure of Drew and Dickerson, are given. In view of the work of Drew and Dickerson, attention is drawn to the presence of clear 004 and 008 reflections in the diffraction patterns of poly[d(I-C)] and poly[d(A-T)]. The available data strongly suggest an 8-fold helical structure for the D-form of DNA.

DNA↗
PubMed1983

Maximum-entropy calculation of the electron density at 4 A resolution of Pf1 filamentous bacteriophage.

A 4 A electron-density map of Pf1 filamentous bacterial virus has been calculated from x-ray fiber diffraction data by using the maximum-entropy method. This method produces a map that is free of features due to noise in the data and enables incomplete isomorphous-derivative phase information to be supplemented by information about the nature of the solution. The map shows gently curved (banana-shaped) rods of density about 70 A long, oriented roughly parallel to the virion axis but slewing by about 1/6th turn while running from a radius of 28 A to one of 13 A. Within these rods, there is a helical periodicity with a pitch of 5 to 6 A. We interpret these rods to be the helical subunits of the virion. The position of strongly diffracted intensity on the x-ray fiber pattern shows that the basic helix of the virion is right handed and that neighboring nearly parallel protein helices cross one another in an unusual negative sense.

Bacteriophages↗
PubMed1983

Benign glandular inclusions in lymph nodes, endosalpingiosis, and salpingitis isthmica nodosa in a young girl with clear cell adenocarcinoma of the cervix.

A 12-year-old girl underwent radical surgery for clear cell adenocarcinoma of the endocervix. Bilaterally dilated fallopian tubes with hyperplastic mucosal folds and salpingitis isthmica nodosa were found in association with benign glandular inclusions in a para-aortic lymph node and in the serosa of pelvic organs. Changes in the müllerian-derived epithelium appear to be a common denominator of these unusual lesions in this young girl. A primary growth disturbance of the cells of the müllerian system, which was conditioned during embryonic development and manifested itself later in life in response to appropriate stimuli associated with menarche, is postulated as the underlying abnormality.

Adenocarcinoma↗