Three-dimensional organization of the lamina reticularis in the rat tracheal basement membrane zone.

The airway basement membrane zone is a region specialized for the attachment of the epithelium with the matrix. The epithelium is attached to the lamina densa, which, in turn, is connected to types I and III collagen of the lamina reticularis with anchoring fibrils. The purpose of this study was to define the three-dimensional organization of the structural proteins of the lamina reticularis in the rat trachea. We approached this problem by using whole mounts to look down on the flat surface of the basement-membrane zone rather than a cross section of its thin profile. Fluorescent microscopy with long working distance water immersion objectives and scanning electron microscopy revealed that the structural proteins are arranged as a mat of large fibers oriented along the longitudinal axis of the airway. Smaller fibers are crosslinked with the larger fibers to complete this structure. Other small fibers are oriented around the large fibers and an amorphous material covers individual fibers. The large fibers oriented along the longitudinal axis of the airway are consistent with prior descriptions of fibers composed of collagen III with some collagen I and V; small fibers encircling the large fibers may be collagen VI. The crosslinking fibers are made up of elastin and probably elastin-associated microfibrils. The amorphous proteins covering the fibrous framework may contain proteoglycans and other nonstructural proteins reported to be in the lamina reticularis. The present studies demonstrate that the structural proteins of the lamina reticularis in the rat trachea are arranged as fibers in a highly organized manner.

Surgical management of nontuberculous thoracic and lumbar vertebral osteomyelitis: report of 33 cases.

BACKGROUND: Thirty-three patients with nontuberculous pyogenic thoracic and lumbar vertebral osteomyelitis were treated surgically. Indications for surgery were either progression of disease despite adequate antibiotic therapy, neurologic deficit, or both. The most common initial symptom was back pain. Seven patients had diabetes, seven patients were intravenous drug users, two patients were receiving immunosuppressive therapy, and seven patients had a debilitating disease. Eleven had infections elsewhere in their bodies. Prior to surgery organisms were grown from blood in 10 patients and at surgery in 15 patients. METHODS: Infection was evident on plain films in all patients, and either a CT scan or MRI was obtained in each. The lateral extracavitary approach was used for resection of granulation tissue and infected bone ventral to the dura. Interbody bone grafts were placed in 19 patients, usually when bone resection was extensive. Posterior instrumentation was placed in 17 patients at a second procedure 10 days-2 weeks following initial operation. Intravenous antibiotics were administered for 4-6 weeks following surgery, and solid fusion was obtained in all patients. RESULTS: Neurologic deficit was present in 28 patients prior to surgery and was functionally significant in 18 patients. Of the 11 patients with severe paraparesis, 10 achieved good functional recovery. These patients were able to walk, three with assistance and seven without, and all those who were unable to void regained this ability. CONCLUSIONS: Surgical debridement, interbody fusion, and posterior instrumentation is a safe and effective treatment for vertebral osteomyelitis and is indicated when neurologic deficit or bone destruction progress despite adequate antibiotic therapy.

Intralesional sustained-release chemotherapy with therapeutic implants for treatment of canine sun-induced squamous cell carcinoma.

Squamous cell carcinoma (SCC) is the most frequently reported malignant epithelial tumour in dogs. Canine sun-induced SCC represents a useful animal model to evaluate new therapeutic modalities for possible human applications. We evaluated the safety and efficacy of treating sun-induced SCC in dogs with intralesional sustained-released chemotherapeutic gel implants that contained collagen, epinephrine (epi), and either 5-fluorouracil (5-FU) or cisplatin (CDDP). Dogs with large, single SCC or fields of multiple SCC were treated with 5-FU/epi gel for a minimum of three weekly injections. Dogs without a complete response were then treated with CDDP/epi gel for a minimum of three weekly treatments. We treated from one to 11 primary, recurrent, or refractory SCC per dog (tumour size 0.2-92.4 cm2; mean cumulative tumour area of 40.7 cm2 per dog). All dogs had at least 50% reduction in cumulative tumour area after treatment with 5-FU/epi gel. More than half (seven of 13) had complete resolution of SCC after treatment with 5-FU/epi gel or CDDP/epi gel. Minimal local tissue reactions were noted; no systemic toxicity occurred. Sustained-release chemotherapy using intralesional 5-FU/epi gel and CDDP/epi gel therapeutic implants is effective in treating canine sun-induced SCC of the skin.

Influence of treatment sequence on efficacy of fluorouracil and cisplatin intratumoral drug delivery in vivo.

PURPOSE: The influence of treatment sequence in combination chemotherapy using fluorouracil (5-FU) and cisplatin (CDDP) was investigated in a mouse tumor model. Both drugs were formulated as therapeutic injectable gels, 5-FU/epinephrine gel and CDDP/epinephrine gel, and used intratumorally in a multiple-treatment regimen. By testing various multiple-treatment regimens, we determined optimal treatment sequences for these two injectable gels. Then we compared the antitumor responses achieved using the optimal treatment sequences for the intratumorally administered gels with the responses obtained using 5-FU and CDDP solutions administered intratumorally or systemically in the same treatment sequence. MATERIALS AND METHODS: Tumor-bearing C3H mice received a total of four injections (every 2 to 3 days from day 0 through day 7) of 5-FU solution, CDDP solution, 5-FU/epinephrine gel, or CDDP/epinephrine gel either as single agents or in various combinations and alternate sequences of solutions or gels. The delay in tumor growth was used as a study end-point. RESULTS: The results showed that local treatment (i.e., intratumoral administration) was more efficacious than systemic treatment (i.e., intraperitoneal administration) when both 5-FU solution and CDDP solution were used either alone or in combination. Further, using two drugs in combination was superior to using either drug alone. When both drugs were delivered intratumorally in the injectable gel formulations, the combination treatment sequences initiated with 5-FU/epinephrine gel were superior to sequences initiated with CDDP/epinephrine gel in delaying the tumor growth. The two sequences initiated with 5-FU/epinephrine gel (i.e., two treatments with 5-FU/epinephrine gel followed by two treatments with CDDP/epinephrine gel and the sequence of alternating 5-FU/epinephrine gel and CDDP/epinephrine gel) showed no significant difference in antitumor efficacy. Both these sequences (initiated with 5-FU/epinephrine gel) produced the longest delays in tumor growth, and > or = 50% (7 of 12) animals remained disease free at the end of the 60-day study. CONCLUSION: These studies demonstrate that significant improvement in local tumor control in mice can be achieved with a simple treatment sequence alteration of two established drugs.

Antitumor effect of intratumoral administration of fluorouracil/epinephrine injectable gel in C3H mice.

Fluorouracil/epinephrine injectable gel (5-FU/epi gel) was evaluated in vitro for its drug-release profile characteristics and in a mouse tumor model for its antitumor effectiveness. In vitro chemosensitivity studies with 5-FU in RIF-1 fibrosarcoma cells showed less than 1 log of cell kill at 1 mM after 2 h of exposure. Increasing the exposure time to 24 h resulted in greater cell killing (approximately 2.5 log cell kill at 0.5 mM), suggesting that sustained drug levels in tumors would result in an increased efficacy outcome in vivo. A 5-FU/epi injectable gel was designed, providing drug release in vitro of 50% by approximately 4 h and of 80% by 24 h. The retention of 5-FU in RIF-1 mouse tumors was determined after intratumoral administration of 5-FU/epi gel or various combinations of the formulation components. Area-under-the-curve (AUC0-24 h) calculations resulted in an AUC value of 146.4% h for the 5-FU/epi gel formulation as compared with 45.7% h for 5-FU solution. Tumor growth was significantly delayed (P < 0.05) with the 5-FU/epi gel (60 mg/kg) as compared with 5-FU solution given intratumorally or systemically. A fluorouracil dose of 150 mg/kg in the 5-FU/epi gel given weekly for 13 weeks was not lethally toxic, whereas the same dose given as drug solution was 100% lethal, suggesting that the therapeutic index for 5-FU in the gel formulation may be much greater than that for aqueous drug solution delivered intratumorally.

Intralesional implant for treatment of primary oral malignant melanoma in dogs.

The feasibility, safety, and efficacy of a new method of local, sustained-release chemotherapy by use of intralesional cisplatin implants were evaluated in the treatment of oral malignant melanoma. The implant is an injectable viscous gel composed of a protein carrier matrix, a vasoactive modifier, and a chemotherapeutic drug. Twenty dogs with biopsy-proven melanomas were treated at 1- to 2-week intervals by injection with cisplatin implant. Tumors were treated until they resolved or were judged to be unresponsive. In 3 dogs with tumors unresponsive to cisplatin implants, methotrexate implants were used, and in 2 of these dogs, carmustine implants followed the methotrexate. Tumor responses were evaluated by sequential measurements. Melanomas in 14 (70%) of 20 dogs had a > 50% decrease in volume, and in 11 (55%) of these dogs, had a complete response. Tumors with complete responses received a mean cisplatin dose of 11.7 +/- 1.8 mg, delivered in a mean of 2.6 treatments. Two of the dogs with complete response also were treated with methotrexate and carmustine. Implants were well tolerated. Local necrosis, limited to the treatment site, developed in most tumors (17/20) and was associated with tumor response. Systemic toxicosis was minimal; renal insufficiency after cisplatin implants was not evident. Median survival times of dogs with complete tumor response (51 weeks) was substantially greater than that of dogs without local tumor control (10.5 weeks). Recursive partitioning analysis of variables indicated that mandibular tumors of short duration were associated with a positive outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of intralesional 5-fluorouracil therapeutic implant (MPI 5003) for treatment of basal cell carcinoma.

BACKGROUND: Basal cell carcinomas (BCCs) are usually treated with ablative procedures. A nonsurgical treatment alternative would be of value in selected patients. OBJECTIVE: We evaluated the safety and efficacy of a new preparation for intralesional sustained-release chemotherapy with MPI 5003, 5-Fluorouracil Therapeutic Implant, for treatment of BCCs. METHODS: Two doses of intralesional MPI 5003 (0.25 and 0.5 ml) were compared in a double-blind study of 20 patients with biopsy-proven BCC. One BCC per patient was treated weekly for up to 6 weeks and followed up monthly for 3 months until excisional biopsy for histologic examination. Before excision the cosmetic appearance of the test site was graded. RESULTS: Eighty percent of 10 BCCs treated with 0.5 ml of MPI 5003 had histologically confirmed cures as compared with 60% of 10 tumors treated with the lower dose (0.25 ml). Cosmetic assessments before excision were typically good to excellent. No systemic side effects occurred. CONCLUSION: Results indicate the potential of MPI 5003 for targeted local chemotherapy for BCC.

Evaluation of the genotoxic potential of sorbic acid and potassium sorbate.

The genotoxic potential of sorbic acid and potassium sorbate was investigated in vivo and in vitro. Oral administration of sorbic acid (up to 5000 mg/kg body weight) did not induce sister chromatid exchanges or the formation of micronuclei in bone marrow cells of mice. Intraperitoneal treatment of rats with 400-1200 mg potassium sorbate/kg body weight did not alter the elution profile of DNA from isolated liver cells in the in vivo alkaline elution assay. Sorbic acid did not induce DNA repair in cultured human A549 cells in the unscheduled DNA synthesis (UDS) assay. In vitro incubation of the cells with 1-1000 micrograms potassium sorbate/ml, in the absence or presence of rat liver homogenate, did not result in the formation of DNA single-strand breaks in the alkaline elution assay. These results demonstrate that sorbic acid and its potassium salt are not genotoxic in vivo or in vitro. In contrast to sorbic acid and potassium sorbate, sodium sorbate is very sensitive to oxidative degradation; the main oxidation product was identified to be 4,5-oxohexenoate, which was mutagenic in the Ames test.

Malignant melanoma in the foot of a horse.

A 24-year-old horse had a malignant melanoma of the right forefoot. Because surgical excision of the melanoma was incomplete, as determined by histologic examination of the excised tissue margins, the tumor margins were injected with a matrix therapeutic implant containing cis-diamminedichloroplatinum, epinephrine, and purified bovine collagen matrix. The foot healed and the horse remained clinically free of disease for 26 months before recurrence of malignant melanoma. Surgical exploration of the digit revealed extensive involvement of the foot, and the horse was euthanatized.

Food applications of sorbic acid and its salts.

Because of their physiological inertness, their effectiveness even in the weakly acid pH range and their neutral taste, sorbic acid and its salts have become the leading preservatives in the food sector throughout the world over the past 30 years. The most commonly used products are sorbic acid itself (E200) and potassium sorbate (E202). In many countries sodium sorbate (E201) and calcium sorbate (E203) are also permitted. Sorbic acid is sparingly soluble in water, sodium sorbate has better solubility, and potassium sorbate is very freely soluble and can be used to produce 50% stock solutions. The soluble sorbates are preferred when it is desired to use the preservative in liquid form, or when aqueous systems are to be preserved. Sodium sorbate in solid form is unstable and very rapidly undergoes oxidation on exposure to atmospheric oxygen. It is therefore not produced on the industrial scale. Aqueous solutions of sodium sorbate remain stable for some time. Calcium sorbate is used in the manufacture of fungistatic wrappers because it is highly stable to oxidation, but this use is very limited. Sorbic acid and sorbates can be directly added into the product. The products can be dipped or sprayed with aqueous solutions of sorbates. Dusting of food with dry sorbic acid is also possible but less recommended because sorbic acid irritates the skin and mucous membranes. Sorbic acid and particularly calcium sorbate can be used as active substances in fungistatic wrappers. A general survey of the numerous uses of sorbic acid in the food sector will be given. Some fields of application will be discussed that are either unimportant or not permitted in the U.K.

Reduction of vinblastine neurotoxicity in mice utilizing a collagen matrix carrier.

Vinblastine sulfate (VLB) suspended within a collagen matrix (CM) as a diffusion limiting drug delivery vehicle was examined in vitro, as well as in mouse subcutaneous and brain tumor models. Against RIF-1 and KHT subcutaneous tumors, there was enhancement of antitumor activity with intratumoral (i.t.) delivery of VLB when it was combined with CM and/or epinephrine (epi) provided as a vasoactive agent to limit diffusion of VLB away from the injection site. Furthermore, in pharmacokinetic studies an 3-fold enhancement of tumor exposure to drug (AUC) with the CM-formulation was observed relative to the administration of free VLB i.t. Craniotactic injection of VLB into mouse brain in doses from 0.2 to 2 mg/kg revealed that the CM association markedly reduced the acute toxicity of VLB in normal mouse brain. Furthermore, mice with stereotactically implanted KHT brain tumors treated with 0.2 mg/kg VLB in CM had less tumor present in the brain histologically compared to the free VLB and untreated control groups.

Improvement of differential toxicity between tumor and normal tissues using intratumoral injection with or without a slow-drug-release matrix system.

The therapeutic effects of cisplatin on tumor and normal tissues were assessed when the drug was given by different administration routes either as free drug or associated with a collagen-based matrix. Tumor response was assessed by growth delay of the murine RIF1 tumor, grown subcutaneously in female C3H/km mice. Normal tissue responses were assessed by plasma clearance of [51Cr]EDTA (giving an estimate of kidney damage), by the drop in peripheral white blood cells, and by a loss in mouse body weight. Intraperitoneal injections of cisplatin were the most toxic to the normal tissues for a given drug dose. Intratumoral injections of matrix-associated drug were the least toxic. Comparison of tumor growth delays for a given normal tissue damage demonstrated the superiority of all intratumoral schedules over the ip route.

Response of murine tumors to matrix-associated cisplatin intratumoral implants.

The response to collagen matrix-associated cisplatin (cis-DDP-CM) implanted intratumorally into KHT and RIF-1 fibrosarcomas grown sc in C3H mice was studied. The effects on tumor growth as well as body weight and animal survival were assessed. The effect of cis-DDP-CM (8 mg/kg) on the growth of KHT tumor was assessed by determining the number of days required for tumors to grow to three times the pretreatment volume of 100-150 mm3. When cisplatin (cis-DDP) was administered ip, the number of days required for threefold growth was 11.1 +/- 2.5 SE. Administration of cis-DDP-CM intratumorally resulted in a value of 17.2 +/- 1.7 days. Epinephrine (0.1-5.0 mg/kg) was also added to the matrix as a vasoconstrictor to further localize the activity of cis-DDP. This resulted in enhanced antitumor activity and, presumably, lower systemic exposure to cis-DDP. For cis-DDP administered ip, the dose required to kill 50% of the test group at 10 days after injection was approximately 14 mg/kg. When cis-DDP-CM was administered intratumorally in doses less than or equal to 30 mg/kg, no mice died. Loss in mouse body weight (greater than 3 g) was detected with ip doses of cis-DDP at 8 mg/kg, but no weight loss was detected for mice treated with matrix implant delivering cis-DDP doses less than or equal to 25 mg/kg.

Effects of matrix-associated chemotherapy in combination with irradiation in vivo.

Delay of tumor growth in RIF-1 fibrosarcomas in C3H mice was studied, comparing ip delivery of 5-fluorouracil (5-FU) or cisplatin (cis-DDP) versus collagen matrix-associated intratumoral delivery of drug with and without irradiation to a total dose of 1,500 cGy. For cis-DDP (6 mg/kg), the number of days required for treated tumors to attain three times their original treatment volume was 6.2 +/- 1.6 SE for ip drug and 7.0 +/- 1.3 for intratumoral drug matrix. The use of the vasoactive agent epinephrine (1 mg/kg) in the matrix resulted in a growth delay of 10.1 +/- 2.0 days. Irradiation given 60 minutes after drug administration enhanced the delay of tumor growth to 19.2 +/- 2.6 days for systemic drug and 16.7 +/- 2.5 days for matrix-associated drug. The delay of tumor growth for irradiation plus matrix-associated cis-DDP containing epinephrine was 33.0 +/- 5.4 days. X-rays alone caused a tumor growth delay of 11.2 +/- 1.3 days. Similar results were found for 5-FU at a dose of 50 mg/kg, although the epinephrine in the matrix was not as effective.

[Food additives from the viewpoint of the food chemist]. / Lebensmittelzusatzstoffe aus der Sicht des Lebensmittelchemikers.

Food additives serve the consumer and are a necessity for food retailers and producers. Additives, such as vitamin D and iodine, increase the nutritional physiological value of foodstuffs. Additives, which improve food preservation by preventing microbiological deterioration are especially important. Some additives are added during food production and have no further use in the finished product. They are no longer present (solvents, clarifying agents). With regard to health, many food additives are better tested than most foods.

[Chemical preservation of food]. / Chemische Konservierung von Lebensmitteln.

Preservation of foodstuffs has always been a necessity for a number of reasons: the durability of food is limited, numerous foodstuffs are only available during a short harvesting season, the transport routes of food or raw materials from the production site to the consumers are continuously increasing in length and the consumers in modern society characterized by division of labor and changed shopping habits increasingly insist on buying durable products. Beyond this, there are medical-hygienic efforts aimed at inhibiting the growth of micro-organisms in food. The hazard to health which many bacteria carry, has been long known. Recently, a number of fungi have been shown to form toxins during their growth on foodstuffs. There are two methods of food preservation: the physical and the chemical. The greater proportion of foodstuffs is rendered durable by physical procedures: drying, cooling, deep-freezing and heating. But chemical preservation also plays a prominent role. The use of preservatives is often combined with physical methods. The application of preservatives has a long history, such as the use of common salt, smoke or sulfur dioxide. Some of these agents, such as benzoic acid, are achievements of the last century. Others, such as propionic acid and sorbic acid, result from research during the last few decades. The preservatives now in use have been thoroughly tested for their toxicological properties. Their use in the food industry is subject to stringent legal regulations. The consumer can be certain of not running any risk by partaking foods which contain preservatives.

Lateral extracavitary approach to the spine for thoracic disc herniation: report of 23 cases.

Twenty-three patients were operated upon for thoracic disc herniation between 1973 and 1982. The lateral approach to the vertebral column was used in each. Most patients had severe local pain; 13 had severe myelopathy or complete motor paralysis, including 4 who had become paraplegic after laminectomy. Eleven patients had calcified discs or osteophytic ridges. Air myelography and computed tomography were diagnostic in all cases. Postoperatively, 17 patients achieved significant relief of pain, 20 improved neurologically, and none became worse. Complications of the operation were minimal. The lateral extracavitary approach to the spine is a valuable technique for the management of thoracic disc herniation.

Chemosensitivity of human neoplasms with in vitro clone formation. Experience at the University of Southern California - Los Angeles County Medical Center.

We analyze experience with 600 specimens for in vitro chemosensitivity assessment of human neoplasms utilizing a soft agar colony-forming technique. Good test reproducibility is demonstrated. Disaggregation with collagenase enhances yield and does not alter chemosensitivity profiles. Therapeutic exposure to chemotherapy prior to biopsy reduces in vitro sensitivity to the specific agents used in vitro. The cyclophosphamide derivatives 4-hydroperoxycyclo phosphamide (4-HC) and phosphoramide mustard are active in vitro, and produce comparable rank order sensitivities among tested tumors. There is marked reduction of in vitro 4-HC sensitivity in patients with prior therapeutic cyclophosphamide exposure, supporting the use of this derivative in test systems. Rank order of test results among specimens is compared at 0.1 microgram and 10 microgram drug/ml. Substantial differences in rank order at these two dose levels are demonstrated, indicating that the in vitro test dose selected is an important variable.