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Biomedical subjects

L Russell

Publications and source records attributed to L Russell.

At least 109 records · Page 6Linked to original sources
PubMed1977

Observations on rat Sertoli ectoplasmic ('junctional') specializations in their association with germ cells of the rat testis.

The ectoplasmic ('junctional') specialization, a subsurface modification of the Sertoli cell that is often seen facing germ cells, was studied in relation to the development and maturation of these germ cells. This structure is composed of subsurface bundles of filaments and more deeply placed endoplasmic reticulum. The data indicate that these subsurface modifications of Sertoli cells are reutilized in a cyclic fashion, being transferred from their position facing late spermatids to one opposing less mature germ cells. Ectoplasmic specializations appeared to function mechanically in grasping the heads of the spermatids which are undergoing the elongation and maturation phases of spermiogenesis rather than in actually attaching Sertoli cells to these germ cells. It is postulated that the ectoplasmic specialization imparts rigidity to that area of the Sertoli cell that surrounds the head region of the germ cell, forming a recess and a mantle by which the germ cell may be moved toward the base or toward the surface of the seminiferous epithelium. The observed linkage of microtubules to the cisternae of the complex provided a morphological basis for the changes in the cytoarchietecture of the Sertoli cell, which must accompany these movements.

Animals↗
PubMed1977

Vinylethylnitrosamine: a potent respiratory carcinogen in Syrian hamsters.

Vinylethylnitrosamine (VEN), an alpha-beta unsaturated analogue of diethylnitrosamine (DEN), which may be formed by the enzymic conversion necessary for carcinogenesis, was synthesized and its biologic effect was examined by sc administration to Syrian hamsters. Distribution studies showed that the maximum amount of unaltered compound was found in various tissues 45 minutes after injection. The chemical was only partially excreted unchanged after 5 hours. Weekly treatment for life resulted in high incidence of malignant respiratory tract neoplasms with short latencies and in tumors of the upper digestive tract and pancreas. The effects of VEN were compared to those of the assumed parent compound, DEN.

Animals↗
PubMed1976

Anchoring device between Sertoli cells and late spermatids in rat seminiferous tubules.

Near the end of spermiogensis, the late spermatids remain attached to the superficial layer of the seminiferous epithelium for an appreciable period of time (i.e., 3 to 4 days). Ths sickle-shaped heads of the spermatids are embedded in an apical process of Sertoli cell cytoplasm which is connected to the rest of the cell by a narrow stalk. In the concavity of the head several long (2-3 mum) and very narrow (50 nm) tubular projections of the spermatid's plasma membrane invaginate the Sertoli cell cytoplasm. These tubular processes terminate by a bulbous swelling which may measure up to 1 mum in diameter. Along the process the plasma membrane of the Sertoli cell is closely apposed to the spermatid's membrane, the intracellular space being only 6-8 nm wide. In the Sertoli cytoplasm immediately surrounding the tubular portion of the structure there is an accumulation of filamentous material, while next to the bulbous extremity there are, at a shrot distance, smooth surfaced cisternae of endoplasmic reticulum. The whole structure was referred to as a tubulobulbar complex. These complexes, of which there are up to 24 per spermatid, appear as these cells complete their migration toward the apex of the Sertoli cells. They disappear just before the release of the spermatids in the lumen of the seminiferous tubule as a result of the fragmentation of the spermatid's plasma membrane followed by a resorption of the Sertoli plasma membrane. Morphological evidence suggests that the Tubulobulbar complexes serve as anchoring devices that retain the spermatids at the surface of the seminiferous epithelium while their dissolution contributes in part to the process of spermiation. Similar tubulobulbar complexes were also formed by the plasma membranes of two adjacent Sertoli cells close to the Sertoli-Sertoli tight junctions near the tubular limiting membrane.

Animals↗
PubMed1976

Sweat gland carcinoma: a clinico-pathological reappraisal.

A case of sweat gland carcinoma arising from the right fifth finger which later metastasized to the regional lymph nodes and the lungs is the subject of this report which attempts to establish further the true characteristics of this definite pathological entity. The diagnosis of sweat gland carcinoma has been loosely applied to a variety of lesions, and it was not until recently that more exact and appropriate criteria were used to establish the diagnosis of sweat gland carcinoma. The case reported in this manuscript possesses most if not all the criteria necessary to make a diagnosis of sweat gland carcinoma. Further review of the literature shows that this is a rare and aggressive neoplasm as this case illustrates. Radical surgery of the primary lesions with radical regional lymph node dissection whenever possible is recommended for the initial treatment, and combination chemotherapy and radiotherapy may be employed in the palliative treatment of the more advanced forms of the disease.

Adenocarcinoma↗
PubMedDate not supplied

The role of nurse-midwives in providing newborn and child care.

The purpose of this exchange is to share the experiences and practices of four nurse-midwifery services that are involved in aspects of newborn and child care. Some examples of historical developments that have influenced the divergent trends in newborn child care in midwifery today are given. The contributors describe special procedures, as well as extended care of newborns as they become infants, children, and young adults. The type and extent of care provided is responsive to the needs and expectations of the families served and to the community in which the service is located. It also reflects the philosophy of the midwifery practice.

Humans↗
PubMedDate not supplied

Physiology of the skin and prevention of pressure sores.

Historically, pressure sores have been seen as a nursing problem, and still are to a certain extent today. Nurses therefore need to have a comprehensive understanding of the physiology of the skin to assist them in preventing and treating pressure sores. Despite a great deal of research on the aetiology of pressure sores, their origins are still not fully understood. This article discusses the physiology of the skin and the aetiology of pressure sores. Influences on pressure sore development are multifactorial and tend to be divided into three main categories: extrinsic (e.g. environmental pressure, shear and friction), intrinsic (e.g. general health, age, mobility, body weight, incontinence and nutrition), and external factors (e.g. long trolley waits in accident and emergency departments or before admission following a long period collapsed on the floor, hard chairs, and immobilization with traction).

Humans↗
PubMedDate not supplied

A review of the Medical Agency Services Confor-Med range.

Medical Agency Services Ltd (MAS) has, since 1994, been involved in the design and development of mattresses and overlays manufactured from visco-elastic polymer foam, which is currently utilized in the manufacture of domestic, automative and specialist bedding and seating products. The foam is fire retardant and satisfies the BS 5852 (Part 2) ignition source 5. The foam is a heat and weight sensitive, visco-elastic polymer, giving a high performance, pressure redistributing surface that 'moulds' to the patient giving simultaneous muscular/skeletal support and allowing the patient to feel comfortable. The Confor-Med mattress offers a sensible alternative for patients with high Waterlow scores who have no pressure sores, but require early intervention to prevent pressure sores developing. A case study is included in this review of the products.

Aged↗
PubMedDate not supplied

Drawtex: a unique dressing that can be tailor-made to fit wounds.

Drawtex is a new and innovative dressing using dispersion technology which works on capillary action. This promotes moist wound healing and provides the optimum environment at the wound interface. This dressing has the ability to absorb exudate 30 times it own weight. The unique capillary action draws the exudate away from the wound bed and into the core of the dressing from where it disperses into a second layer of Drawtex. The practitioner tailors the Drawtex to conform to the wound bed. Drawtex's non-adherence reduces the frequency of dressing change after the first week. This is not the only benefit as it is also very cost-effective at half the price of other modern dressing products.

Absorption↗
PubMedDate not supplied

The importance of wound documentation and classification.

Good wound documentation has become increasingly important over the last 10 years. Wound assessment provides a baseline situation against which a patient's plan of care can be evaluated. A number of documents have been implemented including the 'Code of Professional Conduct for Nurses, Midwives and Health Visitors' (UKCC, 1992), the 'Post-registration Education Project' (UKCC, 1997), 'Standards of Records and Record Keeping' (UKCC, 1998), and 'Keeping the Record Straight' (NHS Executive (NHS E), 1993). These documents require nurses to maintain their professional knowledge and competence, and to recognize any deficiency in their knowledge. Having recognized any deficiency they should read the relevant literature and/or attend a study day on wound care. Nursing records are the first source of evidence investigated when a complaint is made. Wound assessment is very complex and a standardized approach to evaluation needs to be adopted. Such evaluation should encompass colour classification, wound measurement, and classification of tissue type present in the wound. There are numerous methods of measuring wounds; these range from the simple, such as manual estimation by means of a ruler or wound tracing, to the more technical procedures, e.g. computer, image analysis, and colour imaging using hue saturation and intensity. Photography, in conjunction with nursing notes, provides a very good form of wound documentation and can provide clear evidence if required for legal cases.

Diagnosis-Related Groups↗
PubMedDate not supplied

Understanding physiology of wound healing and how dressings help.

One of the most fascinating features of the human body is its ability to repair damaged tissue. When the skin is injured a complex process occurs. The natural healing process can be divided into four distinct stages: inflammatory, granulation, epithelization and maturation. This process can take up to 2 years. Brunner and Suddarth (1992) classified wound healing into three stages: primary; secondary; and tertiary. Many factors affect how long a wound will take to heal, e.g. concurrent illnesses, nutritional status and the dressing used. A holistic approach to wound care is the key, and if all the factors are not addressed then wound healing will not prevail.

Bandages↗
PubMedDate not supplied

A comparison of healing rates on two pressure-relieving systems.

The authors have previously reported the preliminary results of a randomized-controlled trial comparing the relative efficacy of two pressure-relieving systems: Huntleigh Nimbus 3 and Aura Cushion, and Pegasus Cairwave Therapy System and ProActive Seating Cushion (Russell et al, 2000). Although both the mattresses and cushions were effective treatments for pressure ulcers, the Huntleigh equipment was demonstrated to be statistically more effective for heel ulcers, but no differences were demonstrated for sacral ulcers. This article gives a more detailed analysis of the 141 patients assessed using computerized-image analysis of the digital images of sacral ulcers captured during the trial and specifically discusses the healing rates and other patient characteristics. Ninety-eight per cent of ulcers examined were deemed superficial (Torrance grade 2a, 2b, 3). Precision of image analysis assessed by within- and between-batch coefficients of variation was excellent: calibration CV 0.93-1.84%; area CV 4.61-5.72%. The healing rates on the two mattresses were not shown to be statistically different from each other.

Beds↗
PubMedDate not supplied

Malnutrition and pressure ulcers: nutritional assessment tools.

Good nutrition is essential throughout life and often patients have a poor understanding of what a balanced diet comprises. Nurses need to have a good comprehension of malnutrition. Where malnutrition is evident it can be resolved by working with the patient to encourage a healthy diet. One way to improve patient nutrition is by a nutrition audit of patient food. Numerous nutritional assessment tools exist which help to identify a patient's nutritional status. No nationally standardized nutritional assessment tool exists and there is a danger of assessment methods becoming as proliferate as pressure ulcer risk assessment tools. A solution to this problem may be to use a pressure ulcer risk assessment tool with a nutritional risk assessment tool such as the Burton Score. Pressure ulcers and malnutrition have been demonstrated to be strongly correlated with each other. Malnutrition is not just present in hospitals but also in nursing homes. A solution to this problem is to use nutritional tools to highlight nutritional deficiency in a patient's diet not only in hospitals but also in the community and in nursing homes.

Humans↗
PubMedDate not supplied

Overview of research to investigate pressure-relieving surfaces.

Pressure-relieving equipment plays a key role in the prevention and treatment of pressure ulcers. Every year an increasing amount of equipment is launched on to the market. The efficacy of this equipment is traditionally qualified with interface pressure and case studies, but rarely with randomized controlled trials. With the advent of The New NHS: Modern, Dependable (Department of Health (DoH), 1997) and Pressure Ulcer Risk Assessment and Prevention (National Institute for Clinical Excellence (NICE), 2001), a clinical governance system has started to be put into place and hopefully more evidence will be produced by the manufacturers and the NHS. With some 200 different types of mattresses on the market, emphasis needs to be placed on good quality randomized clinical trials to establish effectiveness of what can be costly equipment. This article gives an overview of how, historically, pressure-relieving mattresses were marketed on case studies and interface measurement. Recently, randomized controlled clinical trials are being used to demonstrate the efficacy of the mattress and reduction in the incidence of pressure ulcers. Seating is also an important aspect in continuing 24-hours pressure area prevention and treatment. Patient posture in a chair needs to be fully understood by the practitioner and key strategies are made in this article. Little research into seating has been undertaken and is urgently required.

Beds↗
PubMedDate not supplied

Strikethrough: review of research on mattress cover performance.

During the past few years there have been increasing concerns regarding the performance of pressure-reducing foam mattress covers. Initially, a small number of people observed these problems. However, recently, many more people have begun to identify similar problems with their covers. This article is the result of a collaboration between Medical Support Systems and members of the editorial board of the British Journal of Nursing Tissue Viability Supplement. Medical Support Systems commissioned research from Nottingham Trent University and Cardiff University. The research findings were then passed to members of the editorial board for consideration and the development of this article. The article will present the rationale for the research and the results will be highlighted. It is hoped that it will help inform us and assist those currently working towards a resolution of this problem. The full benefit of this new information will only be felt after an extended debate of not only the results, but also their wider implications.

Beds↗