Growth characteristics of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies.

OBJECTIVE: To determine if there is a difference in in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. To determine the effects of a corticosteroid and monokine on in vitro growth of fibroblasts isolated from the trunk and distal aspect of the limb of horses and ponies. STUDY DESIGN: Growth of fibroblasts from tissues harvested from the trunk and limb were compared from horse and pony samples grown in control media and control media with triamcinolone or monokine added. ANIMALS OR SAMPLE POPULATION: Dermal and subcutaneous tissue from 22 horses and 17 ponies of various ages and breeds. METHODS: Fibroblast growth was assessed by tritiated thymidine uptake using standard cell culture techniques. The effect of a monokine or triamcinolone plus control media were compared with control media for fibroblast growth. RESULTS: Fibroblast growth from tissues isolated from the horse limb was significantly less than growth from the horse trunk and the limb and trunk of ponies. Monokine was more effective than triamcinolone in suppressing fibroblast growth from tissues isolated from the trunk and limb in both horses and ponies. CONCLUSIONS: There are growth differences in fibroblasts isolated from the limb of horses compared with those isolated from the trunk and from the limb and trunk of ponies. CLINICAL RELEVANCE: The difference in fibroblast growth from tissues isolated from the trunk and limb of horses and ponies may provide evidence for the difference reported in the healing characteristics of limb wounds in horses and ponies. Influencing fibroblast growth may provide a key to controlling the development of exuberant granulation tissue in horses and ponies.

Benzalkonium chloride. A potential disinfecting irrigation solution for orthopaedic wounds.

The efficacy of benzalkonium chloride was evaluated as an irrigating solution for the eradication of Staphylococcus aureus from a contaminated orthopaedic wound. Thirty Sprague Dawley rats were randomized into two groups. A stainless steel wire was placed in a lumbar spinous process, and the wound was inoculated with 10(7) or 10(6) colony forming units of Staphylococcus aureus. The wound was irrigated with 1 L of normal saline or 0.1% benzalkonium chloride solution. The animals were sacrificed, and cultures were obtained. Rats inoculated with 10(7) colony forming units of Staphylococcus aureus and irrigated with benzalkonium chloride had a significant decrease in the total number of positive cultures, deep wound cultures, and stainless steel wire cultures. Rats inoculated with 10(6) colony forming units of Staphylococcus aureus and irrigated with benzalkonium chloride also had a significant decrease in the total number of positive cultures, deep wound cultures, and stainless steel wire cultures. In a parallel noninoculation study, histologic evaluation of tissues did not show toxicity in the rats irrigated with benzalkonium chloride. This study shows that benzalkonium chloride is more effective than normal saline as an irrigating agent for eradicating Staphylococcus aureus from a contaminated orthopaedic wound.

The effects of taxol, methylprednisolone, and 4-aminopyridine in compressive spinal cord injury: a qualitative experimental study.

BACKGROUND: Taxol is a diterpene alkaloid that stimulates tubulin production in cells. It may be effective in preserving the cytoskeleton of spinal cord axons after injury. METHODS: Thirty-nine rats were submitted to spinal cord compression. The animals were divided into three groups that received taxol (18.75 mg/m2), methylprednisolone (30 mg/kg), or 4-aminopyridine (1 mg/kg). Taxol was administered as one dose immediately after injury and two additional doses on days 14 and 21. Methylprednisolone was given as a single injection immediately postinjury. Four-aminopyridine was administered on days 25, 26, and 27. A group of nine injured animals served as a control without any treatment. Evoked potentials were recorded before, during, and 4 weeks postinjury. Behavioral tests were measured to evaluate recovery of motor function. RESULTS: The taxol and methylprednisolone-treated animals demonstrated a significant improvement in comparison with the control group. No functional improvement was found at 1 mg/kg treatment of 4-aminopyridine in rats. CONCLUSIONS: We conclude that taxol and methylprednisolone given shortly after the compression injury improve functional outcome after an incomplete spinal cord injury.

In vitro and in vivo effects of activated macrophage supernatant on distal limb wounds of ponies.

OBJECTIVE: To determine whether monokines produced by activated rabbit peritoneal macrophages can inhibit development of exuberant granulation tissue formation in distal limb wounds in ponies. DESIGN: Randomized block. ANIMALS: 5 castrated male ponies, 2 to 6 years old and weighing 140 to 190 kg. PROCEDURE: In vitro activity of cell-free rabbit peritoneal macrophage supernatant was determined after incubation of fibroblasts from the flank and the distal portion of limbs of horses and ponies. Tritiated thymidine was then added, and after reincubation, radioactivity was measured. After creation of a 4-cm2, full-thickness wound on the mid dorsal aspect of each metacarpus and metatarsus of each pony, in vivo activity of the macrophage supernatant was evaluated. Biopsy specimens were collected at random sites near a border of each wound at 4, 6, and 10 weeks after creation of the wounds. Treatment effects were evaluated on the basis of presence of exuberant granulation tissue requiring excision, number of times that excision was required, total area of the wound, epithelialized area, area of granulation bed, and histologic evaluation of the biopsy specimens. RESULTS: The macrophage supernatant effectively inhibited proliferation of equine fibroblasts in vitro. No significant in vivo treatment effects were found among the 4 treatment groups. CONCLUSION AND CLINICAL RELEVANCE: Monokines from stimulated rabbit peritoneal macrophages may have potential for improving wound healing in horses and ponies because of their effective inhibition in vitro of equine fibroblast proliferation.

Origin of muscle action potentials evoked by transcranial magnetic stimulation in cats.

We studied the effects of transcranial magnetic stimulation on ipsilateral and contralateral forelimb extensor muscles in anesthetized cats. A magnetic stimulator, operating at 100% intensity, was used through a circular coil, which was placed tangentially over the midline scalp. Bilateral activation of extensor muscles was readily obtained in all animals. The onset latencies were 7.3 +/- 1.1 and 7.07 +/- 0.8 msec for the contralateral and ipsilateral muscles, respectively. The amplitude of muscle response was unstable in magnitude, nevertheless, it did not show any significant difference between the two sides. The latency of response for ipsilateral and contralateral muscles was similar, which suggests simultaneous activation of motor pathways servicing forelimb muscles. Lesioning or ablation of the motor cortex and decerebration at mid-colliculi level did not abolish the evoked responses elicited at high intensity magnetic stimulation. Stereotactic electrical stimulation of the vestibular nuclei complex was performed, and satisfactory ipsilateral motor responses were obtained. Subsequently, a stereotactic radiofrequency lesion was made at the vestibular nuclei complex, with morphological confirmation. After this lesion, the motor evoked potentials (MEPs) were significantly diminished in amplitude. This finding strongly suggests that the generator of the MEPs resides in the brainstem, mainly at the vestibular nuclei complex.

Homicide facilitated by inhalation of chloroform.

Three related homicides in which each decedent had significant concentrations of chloroform in blood, fat, brain and/or liver are described. The tissue concentrations of chloroform in one of three decedents were within reported lethal ranges. The concentrations in the remaining two decedents were less than lethal but were well above blood levels in nonoccupationally exposed, healthy subjects. The cause of death in one decedent with sublethal chloroform concentrations was suffocation; the cause of death in the other decedent could not be determined with certainty. The manner of death in each case was homicide. Through a review of the literature the authors discuss the history of chloroform as an inhalation anesthetic and the history of chloroform as an agent of abuse, suicide, assault, and homicide. Blood and/or tissue concentrations of chloroform in nonoccupationally exposed, healthy subjects and victims of suicide or homicide from previous reports are compared and contrasted with the amounts in blood and/or tissue in the three subjects described in this study. The authors conclude that, in addition to a direct lethal effect, chloroform may be used to incapacitate a victim of assault who then dies by another cause.

The inhibition of fibroblast proliferation by a novel monokine: an in vitro and in vivo study.

We have identified a product of rabbit macrophages that inhibits fibroblast proliferation. Tested in vitro against several fibroblast populations, this monokine inhibited rabbit conjunctival fibroblast proliferation by 85% (p = 0.005), human conjunctival fibroblast proliferation by 88% (p = 0.005), human hypertrophic scar fibroblast proliferation by 85% (p = 0.005), and human keloid fibroblast proliferation by 79% (p = 0.005). Additionally (in an in vivo model), this monokine was injected into healing rabbit wounds and inhibited fibroblast proliferation by 33% after 7 days (p = 0.0001) and by 27% after 2 weeks (p < 0.0001). Preliminary analysis of the active factor demonstrates that it is not species-specific, has a molecular weight less than 3000 d, is resistant to degradation by trypsin and carboxypeptidase A, is heat-stable, and is produced by macrophages largely in the first 3 days of culture.

Leukotriene B4 is measurable in serum of smokers and nonsmokers.

Leukotriene B4 (LTB4), an arachidonic acid metabolite released by neutrophils and macrophages, helps regulate host immune response to antigenic stimulation. LTB4 affects the chemokinesis, aggregation, and enzyme release of neutrophils and stimulates activity of cytotoxic T cells, natural killer cells, and suppressor T cells. LTB4 also has a positive affect on the margination of monocytes and macrophages in the lung in response to inflammatory stimuli. Cigarette smoking represents an inflammatory stimulus in the lung and affects (decreases) the in vitro release of LTB4 by alveolar, macrophages in comparison with that by alveolar macrophages of nonsmokers. By utilizing a sensitive and specific radioimmunoassay we have detected LTB4 concentrations in serum from smokers and nonsmokers. Furthermore, our preliminary data show mean LTB4 concentrations in the serum of smokers to be nearly 60-fold greater than those in nonsmokers, 211 (SEM 35) vs 3.6 (SEM 1.5). Because systemic quantities of LTB4 are now measurable, quantification of this immune system regulatory may be useful in evaluating inflammatory disease states.

Metacarpophalangeal arthropathy associated with manual labor (Missouri metacarpal syndrome). Clinical radiographic, and pathologic characteristics of an unusual degeneration process.

We describe 7 manual laborers with painful, palpably enlarged metacarpophalangeal joints. Characteristic radiographic changes were joint space loss, prominent osteophytes, and cystic metacarpal heads most prominent in the second and third metacarpophalangeal joints. In 3 of 4 patients, joint biopsy specimens showed subsynovial fibrosis and villous hyperplasia. All 7 patients had similar backgrounds of heavy work demanding sustained gripping motions of both hands, for periods that exceeded 30 years. We designated their condition metacarpophalangeal arthropathy associated with manual labor.

Lack of effect of warfarin on L-thyroxine metabolism.

The effect of a single 50 mg dose of warfarin sodium on thyroxine monodeiodination was examined in eight healthy human subjects. There was no evidence that warfarin inhibits 5'-monodeiodination, although such inhibition exists in rats.

Histopathology of triamcinolone in the subconjunctiva.

Triamcinolone acetonide (TA) was injected subconjunctivally in nine human eyes one week before trabeculectomy. A biopsy specimen of conjunctiva and subconjunctiva was obtained from the site of drug injection, as well as a site 6 mm from the injection at the time of trabeculectomy. The tissue was evaluated by electron microscopy. TA was similarly injected subconjunctivally in ten normal rabbit eyes. For control purposes, six eyes were injected with the vehicle. Five animals were euthanized at one and two weeks post-injection and subconjunctival biopsy specimens from the drug site, at the margin of the drug site, and 180 degrees away from the drug site were subsequently examined by light and electron microscopy. At the drug site in both humans and rabbits, the subconjunctival fibroblasts were necrotic, the collagen fibers were altered in appearance, and there was infiltration of macrophages. The control site was unremarkable. These local morphologic changes may explain, in part, the mechanism(s) of action of injected TA.

Cytomorphological lesions induced by chemotherapeutic agents in transitional cell carcinoma in vitro.

Transitional cell carcinoma from 20 patients and two human cell lines were maintained in short-term tissue culture. Each was studied ultrastructurally before and after incubation with cisplatinum, adriamycin, or mitomycin C. Sequential ultrastructural changes were noted and were found to be specific for each agent tested. Ultrastructural changes in the nucleoli were produced by exposure to cisplatinum or mitomycin C; alterations in the heterochromatin of the nuclei were characteristic of treatment with adriamycin. The changes in the nucleoli seen with cisplatinum have not been described previously and support an alkylating property as a mechanism of action. Intravesical chemotherapeutic agents are now commonly used in clinical treatments. The morphological changes produced by these agents are specific and may be seen in the clinical setting.

Transitional explant reduction assay--a new in vitro testing system for intravesical chemotherapy.

Eighty-five tumors from 49 patients with transitional cell carcinoma were examined in a model for in vitro sensitivity using tumor explant reduction assay. Individual sensitivity patterns were obtained for each tumor tested. Explants were most frequently found to be sensitive to cis-platinum (49 per cent) and least frequently sensitive to thiotepa (20 per cent). Thirteen patients were studied on multiple sequential intervals, with resistance to specific agents noted to develop in 53 per cent of the patients. To date, a prospective cross-over study has been conducted on seven patients with 15 correlates. Overall, clinical correlation of this assay for both resistance and sensitivity is 93 per cent. We report a new assay for transitional cell carcinoma of the bladder that is adaptable to small specimen samples and provides adequate material for testing 73 per cent of the time.

Adaptation of Sinclair swine melanoma cells to long-term growth in vitro.

Sinclair swine melanoma usually regresses in vivo. In the present study, swine melanoma cells were adapted to long-term growth in culture. The morphology of cultured melanoma cells ranged from dendritic to cuboidal, similar to that described for human melanoma cells. Doubling times of the swine melanoma cells were also similar to those of human melanoma cells in vitro. 3,4-Dihydroxy-L-phenylalanine oxidase-positive cells were detected by light microscopy, and melanin and premelanosomes were detected by electron microscopy. Cell cultures could be propagated from progressing, partially regressed, and primary cutaneous lesions, as well as from visceral metastases. Thus, it appears that, under these cell culture conditions, Sinclair swine melanoma cells can be adapted to prolonged growth in vitro.

Malignant melanoma in the Sinclair miniature swine: an autopsy study of 60 cases.

Sinclair miniature swine spontaneously develop multiple cutaneous melanomas which have the ability to metastasize and regress. This study, based on 60 necropsies, documents the similarity of the pathology of the cutaneous malignant melanomas and the organ distribution of metastasis to human melanoma. The invasive cutaneous melanomas have an intraepidermal component analogous to human superficial spreading melanoma. The pathology of the spontaneous regression, characterized by a series of cellular events beginning with a mononuclear inflammatory infiltrate and leading to depigmentation and fibrosis, is likewise similar to cutaneous regression in human melanoma. Just as with human melanoma,metastasis was correlated with deeply invasive cutaneous tumors. Because of both the biologic and histologic similarity of this animal model to human melanoma, the Sinclair miniature swine should serve as an important resource in continuing the study of melanoma.

Heparin-induced thrombocytopenia, thrombosis, and hemorrhage.

Twenty-two patients developed significant thrombocytopenia (5,000 to 96,000/cu mm; mean, 29,000/cu mm) while receiving prophylactic or therapeutic heparin. Seventeen of them developed serious thrombohemorrhagic complications which accelerated the deaths of six and contributed to the late death of one. Cessation of heparin therapy led to an immediate remission of the thrombohemorrhagic complications and thrombocytopenia, with no patient who was not already moribund dying, once appropriate therapy had been instituted. Platelet-count monitoring is recommended for all patients receiving heparin for more than 6 days, with cessation of heparin therapy mandatory for the successful management of patients with this disorder. Evidence is presented for an immunologic etiology for this disorder.

Lymphocyte-tumor cell interaction in patients with head and neck cancer.

Peripheral lymphocytes from 12 patients with squamous cell carcinoma of the lead and neck were incubated with autologous tumor explants. Four of the 12 patients demonstrated lymphocyte induced tumor cytotoxicity. These lymphocytes adhered to the tumor cells and deposited a radioactive label from their surface onto tumor cells. The deposition of this label was associated with tumor death. Tissue sections from those patients who demonstrated lymphocyte cytotoxicity showed a marked plasmacytic infiltration. This was in contrast to non-responders where only a desmoplastic tissue response was observed with few inflammatory cells.