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Biomedical subjects

M Hausman

Publications and source records attributed to M Hausman.

13 recordsLinked to original sources

Arthroscopic treatment of lateral epicondylitis: clinical and cadaveric studies.

Clinical and cadaveric studies were done to investigate the role of a degenerative fringe of the radiocapitellar complex subluxating in the radiocapitellar joint in patients with lateral epicondylitis. In the clinical study, arthroscopic resection of this capsular complex was done. Thirty patients with recalcitrant symptoms of lateral epicondylitis for a minimum of 9 months had surgery. In all patients at arthroscopy, a collar-like band of radiocapitellar capsular complex was found to impinge on the radial head and subluxate into the radiocapitellar joint with manipulation under direct vision. Histologic analyses of the resected tissue showed hyaline degeneration and fibrosis. There were no complications in this series. Twenty-eight patients had complete relief of symptoms by this procedure within 2 weeks of surgery. The average time until return to work was 7 days. Elbow arthroscopy was done in 34 cadaveric elbows to examine the relationship of the annular ligament, the lateral joint capsule, and the radial head. A degenerative capsular fold impinging on the radial head was seen in 15 elbows. A classification system, based on the relationship of the capsular fold to the radial head is described. In Type 1 (19 elbows), the radial head is completely exposed. In Type 2 (six elbows), there is partial coverage of the radial head by the capsuloligamentous complex without interposition into the joint in any position. In Type 3 elbows (six elbows), there is subluxation of the capsular edge into the joint, whereas in Type 4 elbows (three elbows), the radial head is completely obscured throughout the range of motion. The lesion was equally prevalent in men and women. The arthroscopic findings at the time of surgery in the clinical group were the same as the Grade 2 and Grade 3 changes that were seen in cadaveric specimens.

Aged↗

Hepatitis C virus infection in renal failure patients in the absence of anti-hepatitis C virus antibodies.

The magnitude and clinical significance of Hepatitis C virus (HCV) infection in dialysis patients is controversial and underestimated. This study was conducted in order to evaluate the correlation between HCV replication and antibody response to HCV in dialysis patients. HCV infection in dialysis patients was evaluated over a period of 3 years and compared to HCV infection in Liver Clinic patients. Sera were collected from 310 dialysis patients and tested for anti-HCV and HCV-RNA. In addition, HCV genotype and HCV viral load were determined in HCV-RNA-positive sera. Anti-HCV was detected in 43 (14%) of the dialysis patients. Of these, 37 (86%) were HCV-RNA-positive. Among the 267 HCV-seronegative dialysis patients, 25 (9%) were found to be HCV-RNA-positive in more than one sample during the study. These patients were characterized by low viral load; at least two orders of magnitude lower than in the group of HCV-seropositives. In contrast, in the Liver Clinic patients, HCV-RNA was found exclusively in HCV-seropositive patients. Comparison of the genotype pattern in the two groups did not reveal a difference. Our results suggest that HCV infection in dialysis units may be underestimated due to cases of low viral load, depending on the method of RNA extraction and sensitivity of the test used. Low viral load might contribute to the lack of humoral immune response seen in some dialysis patients.

Alanine Transaminase↗

Microvascular applications in limb sparing tumor surgery.

New techniques in microvascular tissue transfer make it possible to "add" bone, muscle, and skin to deficient areas and to maintain and restore function. Clearly, a price is paid, but careful evaluation and judicious weighing of the costs and benefits can vastly expand our reconstructive capabilities. Furthermore, as our knowledge of microvascular anatomy expands, new donor sites with particular attributes and less donor site morbidity are constantly being described. The profusion of new procedures and techniques over the last decade is, perhaps, unparalleled in any surgical specialty. Such techniques not only extend our definitions of what is "salvageable," but also refine our conception of what is functionally or cosmetically acceptable. This enables us not only to extend the indications for limb sparing surgery, but also to move beyond merely "salvaging" extremities to reconstructing functional, cosmetically appealing limbs. These are, to be sure, arduous, complicated cases requiring considerable planning and commitment on the part of the surgeon and the patient, but a successful outcome is extremely gratifying to both parties.

Arm↗

Permanent post-traumatic patellar dislocation.

Permanent post-traumatic dislocation of the patella is an extremely rare condition, and is often confused with congenital dislocation. The anatomic abnormalities differ in the two conditions: in the former there is an adaptive flattening of the patella, in the latter there is a propensity for flexion contractures and incongruity of the patella and trochlea. Treatment options include observation, patellar realignment, and patellectomy. In the patient reported, surgical correction appeared to result in patellar alignment.

Accidental Falls↗

Chemotherapy-induced alterations in the biomechanics of rat bone.

The effects of methotrexate and doxorubicin (Adriamycin) on intact and fractured bone were studied in a rat model. Methotrexate, 0.1 mg/kg i.p., was administered five times a week, or doxorubicin, 1 mg/kg i.v., was given once a week. Animals were killed and evaluated at 4, 8, 12, and 16 weeks after surgical production of a unilateral femoral osteotomy and initiation of the chemotherapeutic program. Both intact and fractured bones were tested to failure in rapid torsion, and the torque, angular deformation, stiffness, and energy were measured. There was a significant alteration in the strength of the healing osteotomies in doxorubicin- and methotrexate-treated animals compared with the control group. The torsional strength of intact bone was not significantly altered by either drug protocol over the period of this observation.

Animals↗

Effect of obstruction on ureteral circumferential force-length relations.

After 2 wk of obstruction, rabbit ureteral length increases by 24%, outer diameter by 100%, and cross-sectional muscle area by 248%. In addition to undergoing muscle hypertrophy, obstructed ureters developed greater circumferential contractile forces than control ureters. The peak active force of obstructed ureteral segments was approximately twice that of control ureters. The increase in force was associated with a corresponding doubling of active circumferential stress (force/unit area), suggesting that the force increase resulted from 1) an increase in contractility rather than being a reflection of the muscle hypertrophy that occurred with obstruction, and 2) muscle fiber reorientation. Thus, the ureter, dilated secondary to 2 wk of obstruction, is not mechanically decompensated bur rather undergoes changes that result in an increase in contractility, Despite muscle hypertrophy and increased contractility, the obstructed ureter's ability to develop the intraluminal pressures required for urine transport decreases. The decrease in intraluminal pressure despite an increase in contractility results from the increased ureteral diameter following obstruction according to the Laplace relationship.

Animals↗

Obstruction induced changes in longitudinal force-length relations of rabbit ureter.

The force-length relationships of rabbit ureters subjected to 2 weeks of obstruction were compared with those of normal rabbit ureters. After 2 weeks of ureteral obstruction, length increased by 24 per cent, diameter by 100 per cent, and cross-sectional muscle area by 248 per cent. At the in vivo length, the resting forces of the control and obstructed ureters were similar. With muscle lengthening, resting force increased. For the same per cent increase over in vivo length, both control and obstructed ureters exhibited the same resting forces. At the in vivo length, the obstructed ureter developed less active force and less stress in response to a suprathreshold electrical stimulus than did control ureters. At the length of maximum force development (1.4 times the in vivo length for both control and obstructed ureters), the force developed by the obstructed ureter was 3.5 times greater than that of the control, yielding a 250 per cent increase over control levels. Thus, active stress (force/unit area) was unchanged after 2 weeks of obstruction.

Animals↗

Immunologic alterations in patients with prostatic carcinoma.

The state of cell-mediated immunity was evaluated in 41 patients with prostatic carcinoma by determining their ability to demonstrate delayed cutaneous hypersensitivity with dinitrochlorobenzene and recall antigens, and to mount an inflammatory response to croton oil, as well as by measuring changes in monocyte chemotactic response. The patients were divided into 2 groups: those with localized disease and those with metastatic carcinoma. Monocyte chemotactic response provides an in vitro quantitative measure of effector cell function and was significantly depressed in the entire group of prostatic cancer patients as compared to non-cancer controls (p less than 0.05). Patients with metastatic carcinoma had a greater defect than those with localized disease (p less than 0.025). After radical prostatectomy a group of patients with localized disease tended to show improvement in monocyte chemotactic response (p less than 0.025). The ability of patients to develop a delayed cutaneous hypersensitivity response was impaired and correlated with the clinical stage of the disease. By using the cutaneous irritant, croton oil, the ability of these cancer patients to mount an inflammatory response was also found to be impaired and showed a close correlation between clinical stage and course of disease. Changes in response to croton oil tended to precede alterations in dinitrochlorobenzene response.

Adult↗

Studies on the immune status of patients with renal adenocarcinoma.

Thirty-one patients with renal carcinoma were divided into 3 groups according to the stage of the disease and evaluated with skin tests to determine cell-mediated immunity and an in vitro chemostaxis assay to measure monocyte function. The patients demonstrated a significant defect in monocyte function, that is the ability to undergo chemotaxis when compared to healthy controls and patients with non-neoplastic disease (p less than 0.001). The defect tended to be more severe in patients with advanced disease. Improvements in monocyte function occurred following nephrectomy in patients with localized disease. The patients were skin tested with recall antigens and dinitrochlorobenzene to determine the presence of a delayed cutaneous hypersensitivity response. Croton oil was used to evaluate the non-specific inflammatory response. These studies indicate that a defect exists in cellular immunity as well as the inflammatory response. Patients with advanced disease tend to be unresponsive to these skin tests while those with localized disease are more likely to react to dinitrochlorobenzene and croton oil.

Adenocarcinoma↗

The temporal and pathological significance of perfusion failure following renal transplantation.

Serial dynamic studies with 99mTc-DTPA are a useful method of monitoring renal transplants. Radionuclide images obtained within 24 hours after surgery and at regular intervals thereafter can identify pathological conditions. The decline or absence of perfusion, coupled with the elapsed time following surgery, can be used to differentiate vascular occlusion or hyperacute rejection from acute rejection, acute tubular necrosis, or accelerated or chronic rejection. 99mTc-pyrophosphate can be used to simultaneously evaluate transplant function and locate possible aseptic necrosis of bone. Both studies are noninvasive and have been performed safely on numerous occasions over a period of several years.

Angiography↗

Latissimus dorsi tendon transfer for massive rotator cuff tears: a cadaveric study.

Certain massive defects of the rotator cuff tendinous insertion cannot be repaired primarily to the greater tuberosity. If restoration of strength is an important treatment goal to the patient, then a tendon transfer may be considered. Ten cadaver shoulders were dissected to define the anatomy of the latissimus dorsi tendon (LDT) and its distance relationship to the axillary and radial nerves with the arm in various positions. The axillary nerve lies superior to the LDT insertion, and the radial nerve passes medial and inferior to the LDT insertion. With the arm internally rotated and the shoulder flexed, the distances from the axillary and radial nerves to the LDT insertion were 2.3 cm and 2.8 cm, respectively. With the arm internally rotated and the shoulder abducted, the distances from the axillary and radial nerves to the LDT insertion were 1.8 cm and 2.0 cm, respectively. Understanding specific anatomic relationships is one of the factors contributing to the safety of the LDT transfer procedure with respect to nerve injury.

Adult↗