Loss of the p16INK4a and p15INK4b genes, as well as neighboring 9p21 markers, in sporadic melanoma.

Although homozygous deletions of the cyclin-dependent kinase inhibitor 2 gene p16INK4a on 9p21 have been reported frequently in metastatic melanoma cell lines, and intragenic mutations within the p16INK4a gene have been detected in familial melanoma kindreds, specific targeting of this gene in the development of sporadic melanoma in vivo remains controversial. Southern analyses were performed in this study to initially assess the frequency of hemi- or homozygous losses of p16INK4a, as well as its neighboring family member, p15INK4b, and other candidate regions within 9p21, in sporadic melanoma. Overall, 22 of 40 (55%) uncultured sporadic melanoma DNAs were determined to harbor deletions of 1-11 markers/genes located on 9p21. This included 10 tumors (25%; 10 of 40) with homozygous deletions limited to either the p16INK4a gene only (20%; 2 of 10), both the p16INK4a and p15INK4b genes (10%; 1 of 10), another novel 9p21 gene, FB19 (10%; 1 of 10), or all three of these genes plus surrounding markers (60%; 6 of 10). In subsequent single-strand conformation polymorphism and sequencing analyses, intragenic mutations in the p16INK4a gene were also revealed in two (10%; 2 of 21) melanoma DNAs that retained one copy of this locus. By comparison, the frequency of pl6INK4a and p15INK4b homozygous deletions, as well as p16INK4a mutations, in melanoma cell lines (analyzed in parallel) was 2-3-fold higher at 61 (23 of 38) and 24% (9 of 38), respectively. These findings indicate that (a) p16INK4a is inactivated in vivo in over one-fourth (27.5%; 11 of 40) of sporadic melanomas; (b) mutation/deletion of p16INK4a may confer a selective growth advantage in vitro; and (c) other 9p21 tumor suppressor genes could be targeted during the development of melanoma.

Chromosome 17 allelic loss and NF1-GRD mutations do not play a significant role as molecular mechanisms leading to melanoma tumorigenesis.

Allelic loss in human cutaneous melanoma has been detected on chromosomes 1p, 6q, 9p, 10q, and 11q. Chromosome 17 contains important tumor suppressor genes such as p53, NM23, and neurofibromatosis type 1 (NF1), which have been implicated in melanoma tumorigenesis. The role of p53 has already been studied by a number of laboratories, showing contrasting results. In the present study, two restriction fragment length polymorphism (RFLP) probes for the NM23 and NF1 genes, together with five other RFLP and four variable number of tandem repeat chromosome 17 probes, were investigated at the loss of heterozygosity (LOH) level in a Southern blot-based assay. The NF1 gene was also tested for LOH by a polymerase chain reaction (PCR)-based approach in two different experiments, using a dinucleotide repeat polymorphic probe at locus D17S250 (17q11.2-q12), and an Alu probe intragenic to the NF1 gene (17q11.2). A PCR single-strand conformation polymorphism assay was included in the study for mutation detection at the NF1-GTPase-activating protein-related domain (GRD). A total of 68 melanocytic tumors were analyzed. LOH was detected in 9 of 87 informative cases (10%). LEW301 (17p11.2-pcen) presented the highest LOH frequency (22%). NM23 showed LOH in 17% of the informative cases, while NF1 did not show either LOH in the Southern blot- and PCR-based experiments or mutations at the NF1-GRD. These results are in concordance with those of previous smaller studies, but when compared with higher LOH frequencies obtained from other chromosomes, these findings indicate that the LOH values found in our study can most likely be attributed to background effect. Thus, chromosome 17 LOH is likely to play and unimportant role as a genetic event in melanoma tumorigenesis. Nevertheless, NF1 merits further study, since homozygous deletions have been detected at this locus in melanoma cell lines.

Image analysis of stage 1 melanoma (1.00-2.50 mm): lymphocytic infiltrates related to metastasis and survival.

Image analysis of histologic sections of 11 patients with clinical Stage 1 melanoma, 1.00 mm-2.50 mm, who developed metastasis, was done to determine the significance of lymphocytic infiltrates relative to metastasis and survival. An age, sex, site, and thickness matched control group of non-metastasizing clinical Stage 1 melanoma revealed no significant difference in the lymphocytic infiltrate parameters from the metastasizing group with the exception of the ratio of lymphocyte infiltrate width to the tumor width (p = 0.003). Increased lymphocytic infiltrates within the tumor and subjacent to its base significantly correlated with delayed time to metastasis (p = 0.014 and p < 0.001, respectively) and longer survival period (p = 0.045 and p < 0.001, respectively). Lymphocytic infiltrate area at the tumor base in relation to tumor area was of prognostic value: the larger the ratio, the greater the time interval from metastasis to death (p = 0.008).

Zinc chloride spray--magnesium hydroxide ointment dual topical regimen in the treatment of obstetric and gynecologic incisional wounds.

A randomized, double-blind, placebo-controlled study was conducted to determine the safety and efficacy of dual topical therapy with zinc chloride spray and magnesium hydroxide ointment in healing incisional wounds. The participants were 100 obstetric and gynecologic patients with abdominal and perineal incisional wounds; 85 completed the treatment regimen, 15 were lost to follow-up. Spray and ointment were applied twice daily and dressings were changed at each application for seven consecutive days. The condition of the wound (the length of the incision, the presence and extent of dehiscence, and signs of infection, such as inflammatory changes and purulent discharge) as well as the degree of pain experienced by the patient were evaluated and recorded on the first, fourth, and seventh days. A more marked decrease in the size of the wound, a shorter healing time, a better control of infection, less dehiscence, and more effective pain control were observed in patients in the treatment group as compared with those in the placebo group. No side effects were noted in patients in either group. The dual topical therapy with zinc chloride spray and magnesium hydroxide ointment proved to be safe and effective in accelerating wound healing in obstetric and gynecologic patients.

Actinomycin D as the primary agent for gestational trophoblastic disease.

Thirty-one patients with nonmetastatic trophoblastic disease (NMTD) and 39 patients with metastatic trophoblastic disease (MTD) of gestational origin were treated primarily with actinomycin D. Complete and sustained remission was achieved with actinomycin D alone in 94% of patients with NMTD and 67% with MTD. In the nonmetastatic group, 93% of patients without choriocarcinoma (non-CCA) achieved remission with actinomycin D, as compared to 100% (only 3 patients) with CCA. in the metastatic group, 76% of patients without CCA achieved remission with actinomycin D, as compared to 56% where CCA was present. Fourteen of the 15 patients who failed to respond completely to actinomycin D alone subsequently responded to methotrexate (10 patients), triple therapy (3 patients), methotrexate plus triple therapy (1 patient), and methotrexate plus vinblastine (1 patient). One patient died with widespread metastases despite intensive chemotherapy with actinomycin D and triple therapy. No serious toxic side effects were encountered even in treated patients with pre-existing laboratory evidence of impaired hepatic function.

A rapid solid-phase radioimmunoassay specific for human chorionic gonadotropin in gestational trophoblastic disease.

A rapid solid-phase radioimmunoassay (RIA) specific for human chorionic gonadotropin (hCG) has been used for the measurement of serum hCG activity in patients with molar pregnancy and gestational trophoblastic disease (GTD). Serum hCG regression as determined by the specific RIA method after evacuation of uncomplicated molar pregnancy was noted to occur over a longer duration of time than previously reported from this Center using a nonspecific RIA system which measures human luteinizing hormone (hLH) and hCG simultaneously. Therapy for proliferative trophoblastic disease was withheld after evacuation of molar pregnancy while the serum hCG level regressed normally, but was instituted when the serum hCG level rose or plateaued for more than two consecutive weeks. Serum hCG levels in patients requiring chemotherapy for GTD were also more accurately monitored with the specific RIA method than with the nonspecific technic. Therapy was based solely on the hCG titer rather than the subsidence of toxicity, as has been our practice in the past. As a result, the duration of hospitalization, total dose of drug required for remission, and toxic side effects were substantially reduced without sacrificing the effectiveness of chemotherapy.