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Biomedical subjects

J M Frank

Publications and source records attributed to J M Frank.

17 recordsLinked to original sources
PubMed2004

Graft repair of the peroneal nerve restores histochemical profile after long-term reinnervation of the rat extensor digitorum longus muscle in contrast to end-to-end repair.

Declining motor function is a prominent feature of ageing physiology. One reason for this is a reduction in plasticity that normally compensates for ongoing reorganization of motor units under physiological conditions. Previous work from our laboratory has shown that microsurgical repair of the transected peroneal nerve is followed by considerable changes in the histochemical profile of the reinnervated extensor digitorum longus (EDL) muscle and that these changes are dependent on both the time and the type of nerve repair. At 6 months postoperatively, a trend toward reversibility could be discerned. In the present work, we analysed the long-term reorganization of histochemical motor unit distribution patterns 15 months after performing either end-to-end repair or grafting of the peroneal nerve in 3-month-old rats. In addition, the EDL muscles of an age-matched control group (age 18 months) were analysed for age-dependent changes. We observed a loss of histochemical organization of motor units leading to an additional fibre type (SDH-INT) in the control group. Fifteen months after end-to-end repair, the histochemical profile showed a decrease in fibre type IIA and an increase in fibre type SDH-INT (P < 0.05), indicating a profound histochemical disorganization of motor units. In contrast, nerve grafting largely restored the histochemical profile of reinnervated EDL muscles. Fibre type grouping was present after both types of nerve repair. These findings show that reorganization of the histochemical profile in reinnervated muscles is dependent on the time and type of nerve repair and is long lasting. In this study, grafting provided superior results compared with end-to-end repair. These long-term results after peripheral nerve repair are influenced by age-dependent changes. Accordingly, nerve repair reduces the normal functional plasticity of motor unit organization. This reduction is enhanced by increasing age.

Aging↗
PubMed1998

Clearance of HSV-2 from recurrent genital lesions correlates with infiltration of HSV-specific cytotoxic T lymphocytes.

The mechanisms involved in host clearance of symptomatic mucocutaneous herpes simplex virus (HSV) infection are unclear. We studied the functional properties of bulk cultures of skin-infiltrating lymphocytes from normal skin and serial biopsies of recurrent genital HSV-2 lesions, and compared HSV-specific and NK responses with viral clearance. HSV-specific CD4+ or CD8+ T cells were rarely detected in lymphocytes cultured from normal skin. The total lymphocyte count and HSV-specific and NK-like effector cell activities were markedly higher in cultures derived from lesional skin. HSV-specific CD4+ proliferative responses and NK-like cytotoxic responses were present at all stages of herpetic lesions, including biopsies early in the disease course. In contrast, cytotoxic T lymphocyte activity was generally low among cells derived from early culture-positive lesions, and increased during lesion evolution. Viral clearance from the lesion site was associated with a high level of local cytolytic activity towards HSV-infected cells. The phenotypes of cells with HSV-specific cytotoxic responses varied between patients, having CD4+ and CD8+ components. Immunotherapeutic approaches to HSV should be directed at improving in vivo cytolytic activity to HSV.

Adult↗
PubMed1998

Recognition of herpes simplex virus type 2 tegument proteins by CD4 T cells infiltrating human genital herpes lesions.

The local cellular immune response to herpes simplex virus (HSV) is important in the control of recurrent HSV infection. The antiviral functions of infiltrating CD4-bearing T cells may include cytotoxicity, inhibition of viral growth, lymphokine secretion, and support of humoral and CD8 responses. The antigens recognized by many HSV-specific CD4 T cells localizing to genital HSV-2 lesions are unknown. T cells recognizing antigens encoded within map units 0. 67 to 0.73 of HSV DNA are frequently recovered from herpetic lesions. Expression cloning with this region of DNA now shows that tegument protein VP22 and the viral dUTPase, encoded by genes UL49 and UL50, respectively, are T-cell antigens. Separate epitopes in VP22 were defined for T-cell clones from each of three patients. Reactivity with the tegument protein encoded by UL21 was identified for an additional patient. Three new epitopes were identified in VP16, a tegument protein associated with VP22. Some tegument-specific CD4 T-cell clones exhibited cytotoxic activity against HSV-infected cells. These results suggest that herpes simplex tegument proteins are processed for antigen presentation in vivo and are possible candidate compounds for herpes simplex vaccines.

Amino Acid Sequence↗
PubMed1997

When walking fails.

Explore the source record for details and available documents.

Physical and Rehabilitation Medicine↗
PubMed1997

Vascular delay in skeletal muscle: a model for microcirculatory studies.

Dynamic myoplasty is a relatively new use for muscle flaps and has led us to revisit the mechanisms of vascular delay as a means of optimizing blood supply to muscle flaps. Despite the well-documented effectiveness of vascular delay in skin flaps, vascular delay in muscle flaps has not been widely reported. Regardless of the many mechanisms postulated in the literature as contributors to the delay effect in skin, the one element common to all these hypotheses is the importance placed on changes in the microcirculation. Based on this factor, in the present study we developed and validated an animal model in which delay-induced microvascular changes could be measured in skeletal muscle flaps. We used the hairless mouse latissimus dorsi muscle flap because its vascular distribution is similar to that of humans and its thin structure will enable us in future studies to directly view and measure its microvasculature using videomicroscopy. In 12 animals, we found that delay significantly (p < 0.01) reduced necrosis of the distal part of the muscle from 57 +/- 9 percent in nondelayed flaps (n = 7) to 22 +/- 3 percent in delayed (n = 5) flaps. In these studies, we also determined that the hairless mouse latissimus dorsi muscle flap will serve as an excellent model for defining microvascular changes throughout delay.

Animals↗
PubMed1997

Is sex of fetus associated with duration of labor in nulliparas?

In a post facto study to examine whether sex of fetus was related to duration of nulliparas' labor 30 nulliparous (had not given birth previously) women who delivered boys and 30 others who delivered girls were matched according to the criteria that they were nulliparous, received an epidural for analgesia during labor, and their labors were either induced or augmented. All delivered vaginally. Duration of labor was not statistically significantly related to sex of the fetus.

Female↗
PubMed1997

Mortality of captive British wartbiter crickets: implications for reintroduction programs.

A fungal infection was identified as the cause of a high mortality rate of captive wartbiter cricket (Decticus verrucivorus) nymphs at the London Zoo (United Kingdom) in 1994. This species is threatened with extinction in the United Kingdom and the animals concerned were part of a captive breeding and reintroduction program. Following these findings, reintroductions were postponed and release sites were used only where there were no extant wartbiter crickets.

Animals↗
PubMed1994

Direct visualization and measurements of wound neovascularization: application in microsurgery research.

Neovascularization or angiogenesis is an essential yet poorly understood component of the healing process. In wound healing research, there is a lack of models enabling quantitative and continuous measurements of wound neovascularization. The hairless mouse ear wound model permits quantitative measurements of wound epithelialization and neovascularization continuously throughout the healing process. On the ears of male homozygous (hr/hr) hairless mice, standardized circular full thickness dermal wounds are produced; then, using vital microscopy, these two processes are directly viewed and measured at day 0 and every third day thereafter until these are complete. This model system and its application to clinically relevant situations are reviewed.

Animals↗
PubMed1994

Microcirculation research, angiogenesis, and microsurgery.

Angiogenesis, the formation of new blood vessels, is essential to a variety of normal and pathologic processes such as wound healing and tumor growth. In microsurgery the development of new vessels between the transferred tissue and the recipient bed is critical to the final outcome of the reconstruction. Several experimental models have been previously developed to study angiogenesis and the effect that new substances have on regulating this process, but they lack the ability to make quantitative measurements. Therefore, we have developed an animal model using the homozygous (hr/hr) hairless mouse ear; by using intravital microscopy and computer-assisted analysis, angiogenesis can be quantitatively measured. Using this model we showed that basic fibroblast growth factor and transforming growth factor beta significantly increased total vessel length by 32% and 63%, respectively, during 20 days following subcutaneous injection. In this paper the importance of angiogenesis research to reconstructive microsurgery is presented and discussed.

Animals↗
PubMed1994

Comparison of the effects of commonly used wound agents on epithelialization and neovascularization.

BACKGROUND: The primary effect sought with most topical wound therapy is antimicrobial. Topical wound agents are thought to promote normal healing by protecting the wound from infection. In this study, we examined the effect of six commonly used topical wound agents (bacitracin, sodium hypochlorite, silver nitrate, silver sulfadiazine, mafenide acetate, and povidone-iodine) on epithelialization and neovascularization in noninfected wounds. For this study, a new wound model was used in which direct visualization and quantification of wound epithelialization and neovascularization were carried out throughout the entire healing process. STUDY DESIGN: We measured the effect which 500 U per g of bacitracin, 0.25 percent of sodium hypochlorite, 0.5 percent silver nitrate, 1 percent silver sulfadiazine, 8.5 percent mafenide acetate, and 10 percent povodione-iodine had on the rate of wound epithelialization and neovascularization. The agents were applied topically to 99 circular full-thickness wounds (2.25 mm diameter, 0.125 mm depth) created on the dorsum of male hairless mouse ears. This model enabled us to visualize and measure directly wound epithelialization and neovascularization repeatedly throughout healing, using intravital video microscopy and computerized digitized planimetry. RESULTS: Control wounds and wounds treated with silver sulfadiazine (n = 18) and mafenide acetate (n = 14) epithelialized in 7.2 +/- 0.7, 7.1 +/- 0.3, and 7.3 +/- 0.3 days, respectively. This was significantly (p < 0.01) faster than the wounds treated with povidone-iodine (n = 10), sodium hypochlorite, (n = 8), and bacitracin (n = 13). Wounds treated with povidone-iodine epithelialized the slowest (11.8 +/- 0.55 days). Wound neovascularization was completed most rapidly in the groups treated with povidone-iodine and silver sulfadiazine (15.0 +/- 0.4 and 15.3 +/- 0.7 days, respectively). This was significantly (p < 0.05) faster than wounds treated with silver nitrate (n = 15), which neovascularized in 18.4 +/- 0.56 days. One-half of the wounds treated with sodium hypochlorite (eight of 16) did not epithelialize or neovascularize. CONCLUSIONS: The various antimicrobial agents studied in our in vivo model affect wound epithelialization and neovascularization differently. These effects on these two very important aspects of healing should be taken into consideration when indicating a specific agent for treatment of different types of wounds.

Animals↗
PubMed1993

Attenuation of facial muscle spasticity with intramuscular phenol neurolysis.

Intramuscular phenol neurolysis is a well-known procedure used to decrease spasticity and improve function in patients who have failed to respond to more conservative forms of intervention. Traditionally, this approach has been limited to spasticity reduction in limb muscles, and its use in managing spasticity of the facial muscles has not been described in the literature. This case report describes a new and previously unreported application of intramuscular neurolysis for managing severe unrelenting facial muscle spasticity in a postanoxic encephalopathic patient. Prior to the procedure, hypertonicity in the orbicularis oris muscle was so profound that it limited speech and affected cosmetic, hygienic, and nutritional status. After intramuscular phenol neurolysis of the orbicularis oris muscle, the patient's level of functioning improved.

Eating↗
PubMed1991

Rehabilitation of physically disabled dentists: a model for a vocationally specific rehabilitation program.

A unique collaborative program whose goal is to facilitate the return of disabled dentists to active dental practice is described. This approach includes comprehensive interdisciplinary evaluation and remediation, and it has succeeded in revealing previously undiagnosed impairments which should be considered in the formulation of a rehabilitation plan. A case report illustrates the process. This program can serve as a model for similar programs addressing the needs of other disabled health care professionals.

Adult↗
PubMed1987

Primary amyloidosis with diffuse splenic infiltration presenting as fulminant pneumococcal sepsis.

This case illustrates a unique clinical presentation of primary systemic amyloidosis, namely, overwhelming pneumococcal sepsis. Although there exists a well-established association between hyposplenism and overwhelming bacterial infection, amyloid replacement of the spleen as a primary cause of the hyposplenism has not been reported. Functional hyposplenism in regard to the effect of the spleen on erythrocytes has been reported in cases of diffuse splenic amyloid infiltration. The patient described had a fulminant course and associated disseminated intravascular coagulation, two clinical features more commonly seen in pneumococcemia occurring in asplenic patients as opposed to patients with normal splenic function. He had no predisposing factors, other than amyloid replacement of the spleen, to account for the development of overwhelming pneumococcemia. The immunologic function of the spleen in protection against overwhelming bacterial infection is briefly discussed.

Amyloidosis↗
PubMedDate not supplied

Selected opioids modify intake of sweetened ethanol solution among female rats.

Water-deprived female rats were given a daily, 1.5-hr opportunity to take either a sweetened ethanol solution or water. Across days, they increased their intake of ethanol solution and had stable intakes of about 2 g of pure ethanol/kg after 3 weeks. Morphine (1.0 mg/kg) alone, and in combination with diprenorphine (25 micrograms/kg), increased intake of ethanol solution among females similar to the increased intake seen with males under similar procedures. Fentanyl dose-relatedly increased intake of ethanol. The data strengthen the idea that one or more of the endogenous opioid systems, but not all, are involved with instances of "excessive" intake of alcoholic beverages.

Alcohol Drinking↗