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Biomedical subjects

M D Liang

Publications and source records attributed to M D Liang.

At least 37 records · Page 2Linked to original sources
PubMed1989

Measurement of capsular contracture: the conventional breast implant and the Pittsburgh implant.

At present, there is no accurate, reliable method of experimentally measuring capsular contracture. This study had four goals: (1) to define the parameters of capsular contracture employing principles of biomechanics of soft tissues, (2) to develop laboratory techniques to measure the parameters, (3) to design an implant that mechanically impedes the process of encapsulation, and, (4) to test this implant against a conventional one. We have developed a breast implant (the Pittsburgh implant) with an altered surface topography. Its silicone shell is punctuated by projections 1 mm in height and 1 mm in diameter. Two techniques were devised to measure contracture. The first involved measuring the force deformation along a coronal axis. The second involved measuring hydrostatic pressures within the implant resulting from the injection of known quantities of saline. Measurements were performed in vivo on 36 animals. By both force and pressure measurements, the Pittsburgh implant showed less capsular contracture (p = 0.12 and 0.012, respectively). Histology revealed that the prototype surface alters the linear arrangement of myofibroblasts and redirects the laminar collagen into a waveform pattern. We conclude from this experimental study that an altered surface topography may serve as a means of rendering a capsule less mechanically effective. We feel that the proposed methods can be used in the laboratory to characterize the extent of capsular contracture.

Animals↗
PubMed1989

Surgical management of difficult wounds of the groin.

Coverage of large defects of the soft tissue of the groin present a challenging problem. Exposure of the femoral vessels or prosthetic grafts requires urgent coverage with well vascularized tissue. The medial and lateral femoral circumflex arteries supply the gracilis, sartorius, vastus lateralis, rectus femoris and tensor fascia lata muscles, permitting the use of these muscles or myocutaneous flaps for coverage of groin defects when the femoral artery is intact. With extensive wounds of the groin resulting from trauma, ablation of carcinoma and vascular reconstruction for atherosclerosis involving the femoral vessels, the aforementioned flaps cannot be used. The external iliac artery supplies the rectus abdominis muscle through the deep inferior epigastric artery and the interal oblique muscle through the deep circumflex iliac artery. These muscle flaps are available when the femoral vessels are not intact. If the ipsilateral iliofemoral vessels are not intact, branches of the contralateral iliac artery through deep inferior epigastric artery and deep circumflex iliac artery provide suitable flaps for covering the groin wound. We review our experience with the management of difficult groin wounds (n = 31) and present a systematic approach to reconstruction of the groin based on these anatomic facts.

Female↗
PubMed1988

Presuturing--a new technique for closing large skin defects: clinical and experimental studies.

We have developed a new technique termed presuturing for aiding in the closure of large skin defects which may have otherwise required a skin graft or flap. This technique is based on biomechanical properties of skin (creep, stress relaxation) which allow skin to stretch beyond its inherent extensibility. Presuturing is performed under local anesthesia and consists of plicating intact skin over the area of planned excision the night prior to operation. Experimental studies in a pig model showed the decrease in force required to close a standard-sized wound to be 40.1 percent less than control (p less than 0.001). Fourteen patients who underwent wide excision of skin lesions had their wounds presutured. All but one wound could be closed primarily without undermining. Presuturing seems to be an easy and clinically useful technique in aiding the primary closure of large defects.

Adult↗
PubMed1988

[Establishment and characteristics of a human synovial sarcoma cell line].

A human synovial sarcoma cell line (HSS-84), from a painful mass excised locally near the left sternoclavicular joint, was established and has been continuously propagated in vitro for more than one year through 54 passages till the end of 1985. Doubling time was 65 hr. The index of mitosis was 28.8%. The chromosome number for most of the cells was hypertriploid. The cells, stored in liquid nitrogen, had a good revival. Cytologically, some cells, showing elongated, spindle, stellate or spidery shape with prominent processes, were arranged in loose or bundled pattern, similar to sarcoma cells; some cells showed ovoid and polygonal in mosaic arrangement, similar to epithelioid cells. Both features indicated biphasic differentiation of the cells. By electron microscopy, the cells consisted of light and dark cells with microvilli and obvious abnormality. Histopathologically, the tumor, from which HSS-84 originated, was a biphasic differentiation synovial sarcoma. It was composed of malignant spindle interstitial cells and malignant epithelioid cells lining the clefts or spaces. The latter was similar to cultured cells by electron microscopy. HSS-84 was identical with the donor. HSS-84 establishment will be useful for research on diagnosis, therapy, origin and biphasic differentiation of the synovial sarcoma.

Animals↗
PubMed1987

[Establishment of a human lung alveolar cancer cell strain and its characteristics].

A human lung alveolar cancer cell strain (HAC-84), isolated from lung adenocarcinoma cell line in Gejiu (GLC-82) by colony selecting method, has been continuously propagated in vitro for more than 2 years through 164 passages till May 1 st 1986. HAC has the typical malignant characteristics as GLC. There are plenty of phospholipid and osmiophilic multilamellar bodies in the cytoplasm of all cells and the membrane-like material in most of the nuclei, which differentiate HAC from GLC and the other types of lung cancers. The cytoplasmic inclusions are the same as those found in type II alveolar epithelial cells of the lung. So, HAC, originated from the type II alveolar cells, is identified as human lung alveolar cancer cell strain. It is significant in the research of the properties and origin of the alveolar cancer, the action and formation of the alveolar surfactants.

Adenocarcinoma↗