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Biomedical subjects

D Berg

Publications and source records attributed to D Berg.

At least 73 records · Page 4Linked to original sources
PubMed1999

Local anesthesia and malignant hyperthermia: review of the literature and recommendations for the dermatologic surgeon.

BACKGROUND: Malignant hyperthermia (MH) is a rare syndrome that is a major cause of anesthetic-related morbidity and mortality in otherwise well patients. The role of local anesthetics, stress, and epinephrine in inducing this syndrome has been subjected to controversy. OBJECTIVE: To examine the role of local anesthetics, stress, and epinephrine in producing clinically relevant adverse effects in patients with MH. METHODS: A critical review of the literature. RESULTS: Local anesthesia is safe for use in usual doses in MH-susceptible patients. The role of stress and epinephrine in precipitating episodes of MH is likely minimal, but controversy remains in the anesthesia and dental literature. CONCLUSION: Recommendations for diagnosis, treatment, and safety precautions to be taken by dermatologic surgeons when treating MH patients are made.

Anesthesia, Local↗
PubMed1999

Chronic fatigue syndrome and/or fibromyalgia as a variation of antiphospholipid antibody syndrome: an explanatory model and approach to laboratory diagnosis.

Chronic Fatigue and/or Fibromyalgia have long been diseases without definition. An explanatory model of coagulation activation has been demonstrated through use of the ISAC panel of five tests, including, Fibrinogen, Prothrombin Fragment 1+2, Thrombin/ AntiThrombin Complexes, Soluble Fibrin Monomer, and Platelet Activation by flow cytometry. These tests show low level coagulation activation from immunoglobulins (Igs) as demonstrated by Anti-B2GPI antibodies, which allows classification of these diseases as a type of antiphospholipid antibody syndrome. The ISAC panel allows testing for diagnosis as well as monitoring for anticoagulation protocols in these patients.

Antiphospholipid Syndrome↗
PubMed1999

Mohs' surgery as an approach to treatment of multiple skin cancer in rhinophyma.

BACKGROUND: Skin cancer arising within a rhinophyma is rare, less than would be expected from the coexisting chronic active inflammatory process. In rhinophyma, multiple coexisting tumours of different histologic types present an unusual challenge and have never been described in the literature. OBJECTIVE: The treatment approach to multiple tumours occurring in rhinophyma, utilizing Mohs' surgery, is reported and discussed. PATIENT: The case of a 64-year-old farmer with basal cell carcinoma, squamous cell carcinoma, and basosquamous carcinoma occurring in the setting of longstanding rhinophyma is described. CONCLUSION: Skin cancer, especially basal and squamous cell carcinoma, diagnosed simultaneously in a rhinophyma creates a challenge; the enlarged, inflamed, and hypertrophied tissue masks their margins. In our opinion, Mohs' micrographic surgery is the treatment of choice and should be primarily considered in view of the malignant potential of these tumours, as is shown by the substantial tumour extension in the case described.

Basal Cell Carcinoma↗
PubMed1999

Three point-advancement closure for skin defects.

BACKGROUND: Circular skin defects are common following Mohs' surgery. Traditional closure (primary, flap, or graft) may involve extensive surgery. Multidirectional advancement closures such as the purse-string closure have been advocated as another useful tool in such cases. OBJECTIVE: To describe a variation on purse-string closure that, in certain cases, is an excellent alternative to other reconstructions, and will provide good cosmetic and functional outcome. METHOD: A three-point anchoring suture is placed after undermining to advance the surrounding tissue toward the centre, creating a "Mercedes Benz" or tripod closure following removal of "dog-ears." RESULTS: Circular wounds in designated areas can be more easily closed, creating well-tolerated, favourable scars. CONCLUSION: Large wounds may be closed with the advantage of avoidance of larger flaps, of decreased wound healing compared to second intention, and of minimizing removal of healthy tissue. An initial trial of closure with this method does not limit subsequent use of other repairs should it be less than satisfactory.

Anesthesia, Local↗
PubMed1999

Overcoming multidrug resistance: valspodar as a paradigm for nursing care.

PURPOSE/OBJECTIVES: To review the mechanisms of multidrug resistance (MDR) in human cancer and the clinical use of MDR modulators to overcome or reverse P-glycoprotein (P-gp)-mediated MDR. DATA SOURCES: Current literature, ongoing clinical trials, and clinical experience. DATA SYNTHESIS: Agents, such as valspodar, that block the activity of P-gp can reverse or overcome MDR caused by overexpression of P-gp. The MDR modulator valspodar (PSC 833; Novartis Pharmaceuticals Corporation, East Hanover, NJ) is examined as a model for establishing nursing guidelines for this new class of therapeutic agents. CONCLUSIONS: The dose of some chemotherapy agents must be modified with concurrent valspodar administration. Studies examining the safety and efficacy of valspodar as a prototype of MDR modulators provide the basis for establishing nursing care guidelines. IMPLICATIONS FOR NURSING PRACTICE: Nursing care for the administration of valspodar includes understanding patient selection, criteria, dosing, and administration; side-effect management; patient monitoring and follow-up; and patient education.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1999

Fast finite element modeling for surgical simulation.

Given the geometric complexity of anatomical structures, realistic real-time deformation of graphical reconstructions is prohibitively computationally intensive. Instead, real-time deformation of virtual anatomy is roughly approximated through simpler methodologies. Since the graphical interpolations and simple spring models commonly used in these simulations are not based on the biomechanical properties of tissue structures, these "quick and dirty" methods typically do not accurately represent the complex deformations and force-feedback interactions that can take place during surgery. Finite element (FE) analysis is widely regarded as the most appropriate alternative to these methods. Extensive research has been directed toward applying the method to modeling a wide range of biological structures, and a few simple FE models have been incorporated into surgical simulations. However, because of the highly computational nature of the FE method, its direct application to real-time force-feedback and visualization of tissue deformation has not been practical for most simulations. This limitation is primarily due to the overabundance of information provided by the standard FE approaches. If the mathematics is optimized to yield only the information essential for the surgical task, computation time can be drastically reduced. Parallel computation and preprocessing of the model before the simulation begins can also reduce the size of the problem and greatly increase computation speed. Such methodologies are being developed in a combined effort between the Human Interface Technology Laboratory (HIT Lab) and the Mechanical Engineering Department of the University of Washington. We have created computer demonstrations which support real-time interaction with simple finite element soft tissue models. In collaboration with the Division of Dermatology, a real-time skin surgery simulator is being developed using these fast FE methods.

Computer Simulation↗
PubMed1998

Expression of type III hyperlipoproteinemia in patients homozygous for apolipoprotein E-2 is modulated by lipoprotein lipase and postprandial hyperinsulinemia.

Type III hyperlipoproteinemia (HLP) is a multifactorial disorder associated with homozygosity for the apolipoprotein (apo) E-2 allele. Factors which may promote the development of HLP include lipoprotein lipase (LPL) and hyperinsulinemia. These factors were investigated in eight patients with type III HLP and in nine normolipidemic controls. In vitro the interaction of apoE with LPL was analyzed in cell binding assays. All type III HLP patients showed delayed triglyceride (TG) clearance and remnant lipoprotein accumulation in an oral fat tolerance test. Normolipidemic apoE-2/2 controls revealed normal TG clearance comparable to apoE3/3 controls. HLP patients showed lower LPL activity and mass than controls. Analysis of the LPL gene revealed an Asn 291-->Ser mutation in three patients and a -93 T-G substitution combined with an Asp 9-->Asn mutation in one control subject. In addition to LPL abnormalities, postprandial hyperinsulinemia was observed in five out of eight patients. In vitro LPL compensated the defective function of apoE-2 in mediating remnant lipoprotein binding to cells. In summary, seven out of eight patients with type III HLP showed LPL abnormalities and/or postprandial hyperinsulinemia. Together with the in vitro data these findings support a coordinate effect of apoE and LPL for the manifestation of type III HLP. Hyperinsulinemia appears to be an additional factor important for disease expression.

Adult↗
PubMed1998

Man-in-the-barrel syndrome caused by cervical spinal cord infarction.

Acute brachial diplegia with normal findings of the legs, "man-in-the barrel" (MIB) syndrome, is generally thought to be caused by bilateral supratentorial brain lesions of the prerolandic cortical and subcortical area. We report 1 patient with a sudden onset of MIB syndrome with no supratentorial lesion but a hemodynamically induced atypical anterior spinal cord infarction after unilateral vertebral artery dissection. Thus, in MIB syndrome an infratentorial lesion site, including the cervical spinal cord, should also be considered.

Acute Disease↗
PubMed1998

Differentiation between intracerebral hemorrhage and ischemic stroke by transcranial color-coded duplex-sonography.

BACKGROUND AND PURPOSE: The differential diagnosis of intracerebral hemorrhage versus ischemic stroke has critical implications for stroke management. Transcranial color-coded duplex sonography (TCCS) has been shown to identify intracerebral hemorrhages and intracerebral vessel occlusions. We conducted this study to evaluate the sensitivity and specificity of TCCS in this differential diagnosis and in the detection of stroke complications. METHODS: One hundred fifty-one patients (58 women, 93 men; mean age, 65.6 years [range, 32 to 89 years] ) with acute hemiparesis were enrolled in this prospective study. On admission all patients had a complete neurological examination. A cranial CT scan and a sonographic examination of the brain parenchyma and all extracranial and intracranial cerebral arteries were conducted. The sonographer was blinded for the radiological findings. RESULTS: According to CT criteria, 60 patients had an intracerebral hemorrhage and 67 patients had an ischemic stroke, and in 24 patients CT findings were inconclusive, showing neither bleeding nor an ischemic stroke. On sonographic examination, 18 patients (12%) had no sufficient acoustic bone window. Of the remaining 133 patients, 126 (95%) were diagnosed correctly by sonography in agreement with CT. Sonography missed 3 atypical bleedings (2 with upper parietal location). In 4 patients without bleeding, an intracerebral hemorrhage was suspected by TCCS because of increased white matter echo density due to microangiopathy. Stroke complications depicted by CT (disturbance of cerebrospinal fluid circulation, hemorrhagic transformation, midline shift, ventricular bleeding) (n=54) were correctly shown by TCCS in 45 patients (83%). No complication was missed that would have required further treatment. CONCLUSIONS: In comparison to the "gold standard" of CT, TCCS identified stroke complications and differentiated between intracerebral hemorrhage and ischemic stroke with reasonable sensitivity. Thus, if CT is not readily available, TCCS may complement clinical examination in patients with acute stroke. In addition, it may also be useful in detecting stroke complications in the follow-up of stroke patients.

Adult↗
PubMed1998

Hair transplantation update.

BACKGROUND: Since the first published description in 1959, hair transplantation has progressed tremendously. OBJECTIVE: This article provides an overview of hair transplantation and a discussion of selected controversies in hair transplantation. METHODS: A review of the literature was undertaken to identify current controversies. RESULTS: Hair transplantation has been refined considerably since it was first performed. As new methods are described, controversies arise. In hair transplantation, these include use of various forms of anaesthesia, the planning of the recipient site, method of harvesting the donor area, megatransplant sessions, isolated frontal forelock transplantation, and use of lasers in hair transplantation. CONCLUSION: Hair transplantation is a time-tested, highly effective, permanent and natural method of improving male-pattern baldness and female alopecia. Improvements in technique continue to be developed, requiring one to keep abreast of changes in the field in order to provide patients with the best hair coverage possible while maintaining a natural appearance.

Alopecia↗
PubMed1998

Irinotecan hydrochloride: drug profile and nursing implications of a topoisomerase I inhibitor in patients with advanced colorectal cancer.

PURPOSE/OBJECTIVES: To review the drug profile and nursing implications of the topoisomerase I inhibitor irinotecan hydrochloride. DATA SOURCES: Published articles, abstracts, professional communications, drug manufacturer, and professional clinical experience with irinotecan clinical studies. DATA SYNTHESIS: Irinotecan, one of the first topoisomerase I inhibitors to gain wide clinical use, has exhibited activity in several malignancies. In June 1996, the United States Food and Drug Administration approved its use in patients with metastatic colorectal cancer refractory to fluorouracil (5-FU)-based therapy. The recommended starting dose is 125 mg/m2 administered as a weekly infusion for four weeks followed by a two-week rest period. The most common and clinically significant adverse events include diarrhea, neutropenia, and nausea and vomiting. Other adverse events include alopecia and fatigue. CONCLUSIONS: Irinotecan has significant activity in patients with 5-FU-refractory colorectal cancer. This drug is well tolerated and easily administered in an outpatient setting. The most common adverse events are well characterized and are reversible upon treatment discontinuation or dosage reduction. In particular, diarrhea, the most common toxicity, is manageable with use of appropriate dose modification and rigorous administration of loperamide at the first signs of diarrhea. IMPLICATIONS FOR NURSING PRACTICE: Nurses need to focus on identifying and managing adverse effects based on individual patient tolerance. Nurses have an important role to play in patient education and follow up in order to minimize toxicity. Patient care concerns include management of diarrhea and nausea and vomiting, neutropenia with related risk of infection, and fluid and electrolyte imbalances.

Antineoplastic Agents, Phytogenic↗
PubMed1998

Managing the side effects of chemotherapy for colorectal cancer.

The treatment of colorectal cancer severely affects both patients suffering from colorectal cancer and their families. To ensure that the patient is fully informed about the impact of colorectal cancer treatment, members of the oncology care team must present to the patient not only potential treatment benefits, but also negative aspects of treatment, such as frequent physician visits, treatment expense, and frequent side effects. Treatment-related side effects not only decrease the patient's quality of life, they also may compromise treatment efficacy by necessitating dosage reductions or interruptions in therapy. Participation by both the oncology care team and patients is crucial for effective side effect management. Methods to reduce the incidence and severity of side effects associated with standard, commercially available chemotherapies for colorectal cancer (ie, 5-fluorouracil-based regimens and irinotecan [CPT-II, Camptosar; Pharmacia & Upjohn Company, Kalamazoo, MI]) are discussed. Brief information about the side effects and management of side effects associated with selected investigational agents, doxifluridine (UFT, Furtulon; Hoffman La Roche Inc, Nutley, NJ), capecitabine (Ro09-1978, Xeloda; Hoffman La Roche Inc), and 5-ethynyluracil (776C85; Glaxo Wellcome Inc, Research Triangle Park, NC) is also presented.

Antineoplastic Agents↗
PubMed1998

Basal cell carcinoma of the conchal bowl: interdisciplinary approach to treatment.

OBJECTIVE: The auricle is the site of only 6% of cutaneous neoplasms, but represents an area of high risk for recurrence. The purpose of this work is to present a series of patients with basal cell carcinoma (BCC) of the conchal bowl, and a review of the literature concerning the management of such patients, and to propose an algorithm for use in the treatment of such cases. METHOD: Nine patients with BCC of the conchal bowl were treated using an interdisciplinary approach. Each patient was assessed by both otolaryngology and dermatology. RESULTS: None of the patients was found to have clinical evidence of significant spread into the external auditory canal (EAC). All were treated with Mohs' micrographic surgery (MMS). In each case, otolaryngology was available to perform en bloc resection of the temporal bone, should the tumour be found to extend significantly into the EAC such that it could no longer be accessed by MMS. None of the patients were found to have such extension. All cases were reconstructed using full-thickness skin grafts. All patients remain free of recurrence at an average follow-up of 12.2 months. CONCLUSION: Based on our experience and a review of the literature, we propose an algorithm for use in the management of BCCs of the conchal bowl. We suggest that an interdisciplinary approach that combines the efforts of otolaryngology and dermatology can provide optimal care by saving patients needless procedures and loss of cosmetically important tissue.

Adult↗
PubMed1997

Preclinical evaluation of biotin labeling for red cell survival testing.

Biotin labeling of red cells was tested in dogs as a preclinical study for cell survival. Red cells were labeled with either spacered Biotin-X-NHS (BxNHS) or water-soluble biotin compounds. After reinfusion, biotinylated red cells were detected in small blood samples (5 microliters) with flow cytometry. Improved BxNHS labeling allows an easy detection of positive red cells for almost 100 days, whereas labeling with watersoluble compounds-despite strong labeling during the first days-results in a decrease of label, which prevented a discrimation between labeled and negative cells after about 4 weeks. When biotin labeling of red cells was compared with 51Cr labeling, slopes of red cell survival were quite similar after the latter were corrected for elution. Survival slopes were linear, and the mean survival time was t = 93 d. In two blood-donor dogs the slopes of red cell survival where log linear and the mean survival time was t = 45 d. In conclusion, BxNHS, but not the water-soluble biotin compounds, is a good nonradioactive, nontoxic alternative for red cell survival studies. No health hazards are to be expected from the very low dose of Dimethylformamide, which is used as a solvent for biotin-x-NHS.

Animals↗
PubMed1997

Fibroblast growth in vitro suppressed by LPS-activated macrophages. Reversal of suppression by hydrocortisone.

Activated macrophages are among the major constituents of the periapical granuloma. Their state of activation may persist for long periods after the local irritant is removed and may delay resolution and repair of the lesion. The effect of activated macrophages on fibroblast growth was studied in vitro. Circular fibroblast colonies were formed using a drop containing 7.5 x 10(5) murine dermal fibroblasts and allowed to grow for 7 days. When peritoneal exudate macrophages were added (0.5-3.0 x 10(6) cells/dish) and activated in vitro by LPS (1 microgram/ml), the fibroblast colony's growth was suppressed. LPS alone, at the concentration used, had no effect on the fibroblast growth. Hydrocortisone (> or = 10(-7) M) totally reversed the suppression, when added either simultaneously with or 6, 24, or 48 h after the LPS. The efficacy of late hydrocortisone treatment suggests that its effect was through prevention of the expression of the LPS activation of the macrophages. These findings may provide a possible clue to a pharmacological modulation of the healing processes that occur in the periapical lesion once its infective source had been eliminated.

Animals↗
PubMed1997

Management of seminoma of the testis: recommendations based on treatment results.

BACKGROUND: The results of management of seminoma of the testis at the Department of Radiation Oncology St Vincent's Hospital, Sydney were evaluated retrospectively to: (i) establish that outcomes were in keeping with published results from centres in Australia and overseas; (ii) assess the impact of chemotherapy on management; and (iii) to determine 'best practice' management protocols based on our results and a review of the relevant literature. METHODS: (i) Assessment of treatment results for stage I and II seminoma of the testis treated by post-orchidectomy radiotherapy and/or chemotherapy at St Vincent's Hospital between 1979 and 1993; (ii) literature review of published data from Australian and overseas centres on the management of seminoma of the testis, and in particular the use of surveillance or chemotherapy either alone, at time of relapse or combined with radiotherapy; and (iii) development of recommendations for use as management protocols in our department. RESULTS: Our data and a review of the literature suggest that post-orchidectomy radiotherapy with chemotherapy for relapse in stage I and IIA disease results in long-term cure rates approaching 100%. Treatment with chemotherapy either routinely or selectively or using a surveillance policy is unlikely to show any improvement in outcome and may be less cost-effective and/or produce increased morbidity and the risk of secondary leukaemia. For stage IIB disease (5-10 cm) the use of initial combination chemotherapy with or without subsequent radiotherapy did not appear to give better outcomes than initial radical radiotherapy alone, reserving chemotherapy or further radiotherapy for relapse. For bulkier stage IIB disease (> 10 cm), the use of initial chemotherapy plus consolidation radiotherapy appeared to be an appropriate treatment. CONCLUSIONS: Management protocols for seminoma of the testis at St Vincent's Hospital, Sydney Department of Radiation Oncology currently are (i) stage I, IIA and IIB (5-10 cm): post-orchidectomy radiotherapy alone with chemotherapy or further radiotherapy for relapse; and (ii) stage IIB (> 10 cm) disease: initial chemotherapy post-orchidectomy followed by radiotherapy to sites of initial disease involvement.

Adolescent↗
PubMed1997

Localized Darier disease. Implications for genetic studies.

BACKGROUND: Darier disease is an uncommon genodermatosis characterized by the symmetrical eruption of keratotic reddish-brown papules occurring in the seborrheic areas of the body. A unilateral, or localized, variant has been identified. We report 4 new cases of localized Darier disease and review the English-language literature. The implications of these cases on future genetic studies are also discussed. OBSERVATIONS: Localized Darier disease occurred with equal frequency in males and females. The average age at onset was 27 years. The most frequent site of involvement was the trunk (40% [16/40]). This condition was aggravated by sunlight, heat, or sweating in 42% (19/40) of reported cases, and 38% (15/40) of the patients responded to treatment with topical tretinoin. CONCLUSIONS: Many of the clinical features of localized Darier disease suggest that it is a genetic mosaic of generalized Darier disease. Further studies of localized Darier disease may therefore prove to be instrumental in the search for the Darier disease gene.

Abdomen↗