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Biomedical subjects

R J Koch

Publications and source records attributed to R J Koch.

At least 37 records · Page 2Linked to original sources
PubMed1998

The failing flap in facial plastic and reconstructive surgery: role of the medicinal leech.

OBJECTIVE: To review the use of the medicinal leech, Hirudo medicinalis, in salvaging the failing, venous-congested flap. A protocol for the use of leeches is presented. Four illustrative cases of failing flaps (pectoralis major, midline forehead, and temporalis) are presented. STUDY DESIGN: Literature review comprised of MEDLINE search 1965 to present. Retrospective review of four cases involving the management of the failing, venous-congested flap. METHODS: A retrospective review of four cases of failing, venous-congested flaps was performed. RESULTS: The authors' experience, as well as the data from the reviewed medical literature, demonstrates the importance of early intervention in order to salvage the failing, venous-congested flap. Leeches are an immediate and efficacious treatment option. CONCLUSIONS: 1. Review of the literature indicates that the survival of the compromised, venous-congested flap is improved by early intervention with the medicinal leech. H medicinalis injects salivary components that inhibit both platelet aggregation and the coagulation cascade. The flap is decongested initially as the leech extracts blood and is further decongested as the bite wound oozes after the leech detaches. 2. When a flap begins to fail, salvage of that flap demands early recognition of reversible processes, such as venous congestion. The surgeon must be familiar with the use of leeches and should consider their use early, since flaps demonstrate significantly decreased survival after 3 hours if venous congestion is not relieved. In the four cases presented, a standardized protocol facilitated early leech use and provided for the psychological preparation of the patient, availability of leeches, and an antibiotic prophylaxis regimen. 3. The complications associated with leech use can be minimized with antibiotic therapy, wound care, and hematocrit monitoring. 4. The use of the medicinal leech for salvage of the venous-congested flap is a safe, efficacious, economical, and well-tolerated intervention.

Aged↗
PubMed1998

Direct bonded orthodontic brackets for maxillomandibular fixation.

OBJECTIVES/HYPOTHESIS: Mandibular fracture treatment often includes arch bar maxillomandibular fixation (MMF), either alone or in combination with open reduction/internal fixation (ORIF) techniques. The glove perforation rate associated with arch bar placement, the incidence of blood-borne pathogen positivity in facial fracture patients, and the injurious effects of arch bars on dental enamel and gingiva have prompted the development of safer alternatives to arch bar MMF. This study evaluates the efficacy, ease of use, and safety profile of one such alternative: orthodontic direct bonded bracket fixation (MMF/DBB). STUDY DESIGN: Prospective study of consecutive mandible fracture patients treated with MMF/DBB. METHODS: Thirty-two patients with mandibular fractures were evaluated from January 1994 to July 1997. Fourteen were appropriate for treatment with MMF/DBB (12 men and two woman; mean age, 24.6+/-7.2 y; range, 16-42 y). Fracture sites included symphysis, angle, condylar neck, coronoid, and body. Nine patients underwent MMF/DBB alone; five underwent MMF/DBB with subsequent ORIF. RESULTS: No infection, malocclusion, malunion/nonunion, or enamel/ gingiva injury occurred. Mean follow-up was 6 months (range, 1-12 mo). Oral hygiene with MMF/DBB was superior to historical controls using arch bars. CONCLUSIONS: MMF/DBB can serve as the single treatment method with satisfactory results in patients with favorable, less complicated mandible fractures, although with increased experience, we have treated several more complex cases with MMF/DBB alone. In cases necessitating ORIF, MMF/DBB can be performed preoperatively to align fracture segments and reestablish occlusion. This facilitates placement of osteosynthesis plates and reduces ORIF operative time. MMF/DBB is an economical, safe technique that minimizes blood-borne-pathogen risk to the operative team, eliminates periodontal injury, facilitates postoperative dental hygiene, and is painless to apply and remove.

Adolescent↗
PubMed1998

Advantages and disadvantages of computer imaging in cosmetic surgery.

BACKGROUND: Despite the growing popularity of computer imaging systems, it is not clear whether the medical and legal advantages of using such a system outweigh the disadvantages. OBJECTIVE: The purpose of this report is to evaluate these aspects, and provide some protective guidelines in the use of computer imaging in cosmetic surgery. METHODS: The positive and negative aspects of computer imaging from a medical and legal perspective are reviewed. Also, specific issues are examined by a legal panel. RESULTS: The greatest advantages are potential problem patient exclusion, and enhanced physician-patient communication. Disadvantages include cost, user learning curve, and potential liability. CONCLUSION: Careful use of computer imaging should actually reduce one's liability when all aspects are considered. Recommendations for such use and specific legal issues are discussed.

Communication↗
PubMed1998

Initial clinical evaluation of the NovaScan carbon dioxide laser handpiece.

BACKGROUND: This report summarizes an institutional review board-approved 6-month study with the NovaPulse carbon dioxide (CO2) laser utilizing the NovaScan handpiece in facial skin resurfacing applications. OBJECTIVE: This study comprised the initial clinical evaluation (pre-FDA approval) of this device. METHODS: A total of 54 patients underwent 56 laser procedures: 36 full face and 20 regional procedures. RESULTS: Following healing, there was a 91% satisfaction rate. The mean laser-on times were: full face, 27 min; perioral, 7 min; periorbital, 3 min; glabellar, 2.5 min; scar, 5 min; and epidermal lesions, 6 min. CONCLUSIONS: The NovaScan CO2 laser handpiece is a safe tool for skin resurfacing. In its initial use over a 6-month period there were no device-related complications.

Dermatologic Surgical Procedures↗
PubMed1997

CD4+ T cells from IRF-1-deficient mice exhibit altered patterns of cytokine expression and cell subset homeostasis.

Interferon regulatory factor-1 (IRF-1) is a member of a family of transcription factors that regulate an array of genes involved in cell growth, differentiation, and death. Analysis of cytokine expression by stimulated CD4+ cells from IRF-1(-/-) and IRF-1(+/+) mice revealed that IRF-1 deficiency resulted in an elevated production of Th2-related cytokines and a compensatory decrease in the expression of naive cell- and Th1-related cytokines. The altered cytokine profiles of IRF-1(-/-) cells could be explained, in part, by a shift in the representation of subsets of CD4+ cells; IRF-1(-/-) mice exhibited a decreased percentage of naive cells (a major source of IL-2) but increased numbers of memory or effector cells (the source of Th2-related cytokines). We analyzed purified, phenotypically matched memory/effector cells from IRF-1(-/-) and IRF-1(+/+) mice and found that the increased Th2:Th1 cytokine ratio was still evident in the IRF-1(-/-) group, thus suggesting that IRF-1 is involved in the polarization of the cytokine repertoire in CD4+ cells. Our data indicate that IRF-1 plays an important role in the maintenance of CD4+ cell subset homeostasis and in the expression of cytokines by naive and memory/effector cells.

Animals↗
PubMed1997

Transcalvarial suture fixation for endoscopic brow and forehead lifts.

OBJECTIVE: To evaluate the safety and effectiveness of transcalvarial suture fixation during endoscopic repair of brow ptosis. DESIGN: Case series. SETTINGS: A private ambulatory surgicenter and a Veterans Affairs Hospital. PARTICIPANTS: Fifty patients with brow ptosis with minimum follow-up of 12 months. RESULTS: Patients had improvement in brow position in all cases. There were no adverse effects of performing cortical tunnels and suture fixation. CONCLUSION: Transcalvarial suture fixation can be performed safely with good to excellent results and avoids the need for screw or plate fixation.

Endoscopy↗
PubMed1997

Distortion of the auriculocephalic angle following rhytidectomy. Recognition and prevention.

Distortion of ear protrusion after rhytidectomy results in an aesthetically unfavorable appearance. We have seen cases in which the auriculocephalic angle has widened postoperatively, producing a noticeable deformity. Herein, we report 3 cases that resulted in abnormal postsurgical ear protrusion. We also discuss prevention through the use of conchal setback sutures.

Adult↗
PubMed1997

Contemporary management of the aging brow and forehead.

Management of the aging brow and forehead has recently evolved based on available innovative technologies. Likewise, procedure-specific indications have changed based on collective surgical experiences. No longer is the approach based solely on hair pattern or degree of brow ptosis. Patients require varying combinations of brow elevation (prior to blepharoplasty), correction of brow asymmetries, and hairline-preserving forehead elevation. Some may only require excisional or paralytic procedures of the frontalis muscle (horizontal forehead creases), corrugator supercilii muscles (vertical glabellar furrows), and procerus muscle (horizontal glabellar furrows). We present a 3-year experience using a problem-specific approach. This incorporates endoscopic technology, botulinum toxin type A purified neurotoxin complex (Botox, Allergan, Irvine, CA) intramuscular injection, and traditional procedures such as the coronal, pretrichial, midforehead, and direct browlift. Current indications, patient selection, and results are also discussed.

Aging↗
PubMed1997

Serum-free keloid fibroblast cell culture: an in vitro model for the study of aberrant wound healing.

The purpose of this study was to develop an in vitro serum-free keloid fibroblast model. Keloid formation remains a problem for every surgeon. Prior evaluations of fibroblast characteristics in vitro, especially those of growth factor measurement, have been confounded by the presence of serum-containing tissue culture media. The serum itself contains growth factors, yet has been a "necessary evil" to sustain cell growth. The design of this study is laboratory-based and uses keloid fibroblasts obtained from five patients undergoing facial (ear lobule) keloid removal in a university-affiliated clinic. Keloid fibroblasts were established in primary cell culture and then propagated in a serum-free environment. The main outcome measures included sustained keloid fibroblast growth and viability, which was comparable to serum-based models. The keloid fibroblast cell cultures exhibited logarithmic growth, sustained a high cellular viability, maintained a monolayer, and displayed contact inhibition. Demonstrating model consistency, there was no statistically significant difference between the mean cell counts of the five keloid fibroblast cell lines at each experimental time point. The in vitro growth of keloid fibroblasts in a serum-free model has not been done previous to this study. The results of this study indicate that the proliferative characteristics described are comparable to those of serum-based models. The described model will facilitate the evaluation of potential wound healing modulators, and cellular effects and collagen modifications of laser resurfacing techniques, and may serve as a harvest source for contaminant-free fibroblast autoimplants. Perhaps its greatest utility will be in the evaluation of endogenous and exogenous growth factors.

Cell Division↗
PubMed1997

Legal issues of computer imaging in plastic surgery: a primer.

Although plastic surgeons are increasingly incorporating computer imaging techniques into their practices, many fear the possibility of legally binding themselves to achieve surgical results identical to those reflected in computer images. Computer imaging allows surgeons to manipulate digital photographs of patients to project possible surgical outcomes. Some of the many benefits imaging techniques pose include improving doctor-patient communication, facilitating the education and training of residents, and reducing administrative and storage costs. Despite the many advantages computer imaging systems offer, however, surgeons understandably worry that imaging systems expose them to immense legal liability. The possible exploitation of computer imaging by novice surgeons as a marketing tool, coupled with the lack of consensus regarding the treatment of computer images, adds to the concern of surgeons. A careful analysis of the law, however, reveals that surgeons who use computer imaging carefully and conservatively, and adopt a few simple precautions, substantially reduce their vulnerability to legal claims. In particular, surgeons face possible claims of implied contract, failure to instruct, and malpractice from their use or failure to use computer imaging. Nevertheless, legal and practical obstacles frustrate each of those causes of actions. Moreover, surgeons who incorporate a few simple safeguards into their practice may further reduce their legal susceptibility.

Communication↗
PubMed1996

Combined use of superpulsed carbon dioxide laser and cryotherapy for treatment of facial rhytids.

OBJECTIVE: To compare the effect of superpulsed carbon dioxide (CO2) laser alone with that of cryotherapy in combination with CO2 laser in treatment of facial rhytids. DESIGN: A randomized prospective study. SETTING: Facial Plastic Surgery Clinic at Standford University Medical Center, Standford, Calif. PATIENTS: Twenty patients with perioral rhytids were randomized in the study, 11 in the laser group and 9 in the cryotherapy and laser group. INTERVENTION: Patients in the laser group were treated with superpulsed CO2 laser. Initially, the shoulders of rhytids were spot treated. The area was then wiped and rehydrated. The entire surface was then treated with a second pass. A third pass, if deemed necessary, was then used to treat the shoulders. Patients in the combined group underwent cryotherapy of the entire perioral region followed by CO2 laser treatment similar to that previously described. MAIN OUTCOME MEASURE: Improvement in facial rhytids with laser treatment alone was compared with improvement using cryotherapy and laser. A skin wrinkle grading system was used and patients were graded by 3 independent observers. Close-up photographs were obtained preoperatively and postoperatively. A questionnaire was filled out by each patient 1 month following treatment and was used to rate overall patient satisfaction. RESULTS: There was no statistically significant difference between the 2 groups regarding final outcome, amount of anesthetic agents required for each patient, or rate of complications. CONCLUSION: Superpulsed CO2 skin resurfacing alone is as effective as combined cryotherapy and superpulsed CO2 laser for treatment of perioral rhytids.

Cryotherapy↗
PubMed1995

Access to the superior mediastinum.

Surgical access for diseases that involve the superior mediastinum can be achieved without thoracotomy by utilizing the suprasternal approach with extension of the head and neck and transection of the interclavicular ligament, median sternotomy, resection of the medial third to one half of the clavicle, or resection of the manubrium sterni. There has been minimal morbidity and no operative or postoperative mortality in a review of 53 consecutive patients. There has been no significant disability. Combined with exposure at the base of the neck, the access to the superior mediastinum is good to excellent.

Clavicle↗
PubMed1995

Qualitative and quantitative immunoglobulin production by specific bacteria in chronic tonsillar disease.

Tonsillar tissue lymphocyte (TTL) function as measured by immunoglobulin production was assessed in vitro in 60 tonsils, 51 diseased and 9 normal controls. The diseased specimens were from children (aged 3 to 10 years) clinically classified as having recurrent tonsillitis (RT), idiopathic tonsillar hyperplasia (ITH), or recurrent tonsillitis with hyperplasia (RT/H). TTLs were challenged with intact, heat-inactivated bacteria found in the core of diseased tonsils--Streptococcus pyogenes (SP) and Haemophilus influenzae type B (HIB) as well as the dominant bacterium (DB) grown from that particular tonsillar core. The phytomitogen, leukoagglutinin (LA), was used as a nonspecific activator. Qualitative immunoglobulin production was assessed for the immunoglobulin G (IgG), immunoglobulin M (IgM), and immunoglobulin A (IgA) classes. Immunoglobulin-specific production was quantified at the basal level, and at 2, 4, and 6 days following stimulation. Stimulation with HIB produced the greatest amount of IgG and IgM in TTLs from control tonsils. The DB was a relatively weak stimulator of normal (control) TTLs, yet produced relatively brisk IgG responses in the RT and ITH categories. It did, however, yield only marginal IgM secretion in these groups. IgA was consistently produced after stimulation in diseased TTLs, yet was not elicited from normal TTLs. The aforementioned findings suggest a differential qualitative and quantitative immunoglobulin response for healthy, recurrently infected, and hyperplastic tonsils. Lymphocyte hypofunction along with structural changes associated with hyperplasia may be central to the etiology of chronic tonsillar disease. The tonsillar immunologic response in disease and health is discussed.

Agglutinins↗
PubMed1993

Patterns of cytokine gene expression by CD4+ T cells from young and old mice.

We have analyzed the patterns of induced cytokine gene expression and cell cycle activity by CD4+ cells from mice, and have examined how these response patterns change during the aging process. CD4+ cells were isolated from spleens of young adult and old C57BL/6NNia mice and were stimulated in vitro with plate-bound anti-CD3 epsilon mAb. The cells were then assessed over time for the capacity to accumulate transcripts for IL-1 alpha, IL-1 beta, IL-2, IL-3, IL-4, IL-5, IL-6, IFN-gamma, TNF-alpha, and TNF-beta; to secrete IL-2, IL-3, IL-4, IL-5, IL-6, and IFN-gamma; and to progress through S phase. Before the first major cell division in culture (< 32 h), stimulated CD4+ cells of the old group contained similar peak levels of IL-2, TNF-alpha, and TNF-beta transcripts relative to young adult controls, whereas IL-3, IL-4, IL-5, and IFN-gamma transcripts accumulated to significantly higher peak levels in the old group. These findings were consistent with the patterns of cytokine secretion later in culture (24 to 72 h): the peak IL-2 levels were similar between age groups, but the old group exhibited an enhanced capacity to release IL-3, IL-4, IL-5, and IFN-gamma. In contrast, CD4+ cells of the young group were superior in the hyper-expression of the housekeeping gene, rpL32, before cell division and in the levels of S phase activity throughout 3-day cultures. Similar analyses of CD4+ cells from mice of intermediate ages showed that the alterations in cytokine profiles occurred gradually from young adulthood to old age, whereas the reductions in proliferative capacity were late life changes. Consistent with previous reports, we found that the splenic CD4+ cell group also underwent a progressive, age-dependent increase in the proportions of cells expressing high levels of membrane CD44 (a phenotype associated with memory or effector cells). Moreover, the analysis of IL-3, IL-5, and IFN-gamma production by isolated CD4+CD44lo and CD4+CD44hi cells revealed that the capacity to produce these cytokines segregated predominantly with the CD44hi subset, regardless of donor age. Taken together, our data suggest that gradual age-associated shifts in the subset composition of the splenic CD4+ cell pool underlie progressive changes in the patterns of cytokine gene expression by this cell group.

Aging↗
PubMed1993

Bacteriology and immunology of normal and diseased adenoids in children.

Adenoid physiology as reflected in the qualitative and quantitative bacteriology and immune cell distribution was correlated with clinical presentation in 69 children (16 to 130 months of age) undergoing adenoidectomy for obstructive adenoid hyperplasia (n = 38) or chronic adenoid infection (n = 31) and in 16 adenoid core biopsy specimens from 16 nondiseased controls. In the control adenoids, few potentially pathogenic bacteria were found as the dominant bacteria in the adenoid core (25%), and significantly greater concentrations of nonpathogens (commensals) were isolated (P < .01). Potential pathogens as the dominant bacteria were found twice as often in obstructive adenoid hyperplasia (62%) and in chronic adenoid infection (55%) (P < .05). Haemophilus influenzae was most common in the diseased adenoids, 53% in obstructive adenoid hyperplasia and 48% in chronic adenoid infection, compared with only 19% in the controls (P < .05). No significant differences in lymphocyte density, B and T cells, as well as T-helper subsets, were found between clinical classifications. However, T-suppressor cells, monocytes-macrophages, and natural killer cells were significantly increased in chronic adenoid infection only (P < .05). The findings in this study support roles for both alterations in bacterial homeostasis and an altered immune profile in the etiology of chronic adenoid disease in children.

Adenoids↗