Search PubMed⌕ Search

Biomedical subjects

H Kashtan

Publications and source records attributed to H Kashtan.

79 records · Page 5Linked to original sources
PubMed1985

Stress fractures in military recruits. A prospective study showing an unusually high incidence.

In a prospective study of 295 male Israeli military recruits a 31% incidence of stress fractures was found. Eighty per cent of the fractures were in the tibial or femoral shaft, while only 8% occurred in the tarsus and metatarsus. Sixty-nine per cent of the femoral stress fractures were asymptomatic, but only 8% of those in the tibia. Even asymptomatic stress fractures do, however, need to be treated. Possible explanations for the unusually high incidence of stress fractures in this study are discussed.

Adolescent↗
PubMedDate not supplied

In vitro and in vivo effects of photodynamic therapy on murine malignant melanoma.

BACKGROUND: The role of photodynamic therapy (PDT) in the treatment of malignant melanoma is not well defined, nor is it known whether the dark melanoma cells absorb the light used in PDT. METHODS IN VITRO STUDIES: 2 x 10(5) B16 murine melanoma cells were incubated with aluminum phthalocyanine (AlpcS4, 2.5 mg/kg) and were then subjected to photoradiation (50, 100 or 200 J/cm2). Viability was then assessed. In vivo studies: HISTOLOGY: C57/B1 mice received 2 x 10(5) B16 cells subcutaneously and were randomized into study (PDT) and three control groups. AlpcS4 2.5 mg/kg was injected intraperitoneally and the mice were exposed to light (100 J/cm2). After 24 hours they were sacrificed and underwent autopsies. Survival: 40 mice were randomized into PDT (40 J/cm2) and control groups and were monitored for 50 days. Tumor growth: 40 mice were randomized into one control and three treatment groups (PDT on day 3, 6, or 12 after injection with B16 cells), and were monitored for 50 days. Temperature: Tumor temperatures before and at the end of PDT were recorded. RESULTS IN VITRO STUDIES: PDT caused a decrease in cell viability to 15.5 +/- 0.7%, 11.5 +/- 2.1%, and 1.5 +/- 0.7% (at 50, 100, and 200 J/cm2, respectively; P < .001). A significant reduction in thymidine incorporation was noted at all energy levels. In vivo studies: HISTOLOGY: PDT caused massive tumor necrosis. Survival: PDT prolonged the survival of mice (41 +/- 13.4 days) compared to controls (15.8 +/- 3.8 days, P < .001). Tumor growth: 31 days after injection with B16 cells, the tumor size was 2.6 +/- 0.3 cm in the control group and 1.6 +/- 0.2, 0.9 +/- 0.3, and 1.0 +/- 0.4 cm in the PDT groups (days 3, 6 and 12, respectively; P < .01). Temperature: PDT increased skin temperature to 42.8 degrees C +/- 1.3 degrees C, 45.3 degrees C +/- 3.5 degrees C, and 51.7 degrees C +/- 2.7 degrees C at 40, 60, and 100 J/cm2, respectively (P < .01). CONCLUSIONS: Photodynamic therapy was found to have significant effects in experimental melanoma in mice. The role of PDT in human melanoma remains to be studied.

Animals↗
PubMedDate not supplied

Effect of photodynamic therapy on normal fibroblasts and colon anastomotic healing in mice.

Photodynamic therapy as an adjuvant modality to surgical resection of colon cancer is feasible provided that it does not affect healing of the anastomosis. The aim of this study was to evaluate the effects of photodynamic therapy on the viability of normal fibroblasts and on the healing process of colonic anastomosis in mice. Both in vitro and in vivo methods were employed. For in vitro study, 2 x 10(to the fifth power); human fibroblasts were incubated in triplicate with 5-aminolevulinic acid (2.5 microg/well) for 48 hours. Cells then underwent photoradiation at light doses of 50, 100, and 200 joules/cm(2) using a nonlaser light source. Viability was assessed by methylene blue dye exclusion. For in vivo studies, 60 mice were randomized into study and control groups and underwent laparotomy involving colonic anastomosis. The anastomosis underwent photodynamic therapy using 5-aminolevulinic acid (60 mg/kg) as a photosensitizer and a nonlaser light (40 joules/cm(2)). On postoperative days 1, 4, 7, 14, and 21, six mice were killed and subjected to bursting pressure and histologic examinations. Results of in vitro study showed pretreatment cell viability to be 96% to 99% in both groups. Photodynamic therapy caused no significant change in fibroblast viability at all light doses. Results of in vivo studies showed that the mean bursting pressure of both groups dropped to a low peak on day 4. Subsequently there was a gradual increase in bursting pressure along the examined time points (P <0. 001). There was no difference in bursting pressure between the two groups for all time points examined. It was concluded that photodynamic therapy has no effect on viability of normal human fibroblasts and no adverse effects on healing of colonic anastomosis.

Aminolevulinic Acid↗
PubMedDate not supplied

Continuous intravenous octreotide treatment for acute experimental pancreatitis.

BACKGROUND: The efficacy of octreotide, the synthetic analogue of the hormone somatostatin, for the treatment of acute pancreatitis is controversial. Octreotide has been commonly administered in subcutaneous bolus injections; however, continuous intravenous infusion may be advantageous for acute conditions. METHODS: Acute experimental pancreatitis was induced in rats by intraparenchymal injections of 1 ml 10% sodium taurocholate, and octreotide (1 microg/kg/h, dissolved in physiological solution, intravenously was started 4 h later and continuously infused for 48 h. Physiological solution infusions, in identical volumes, were used in the controls. The following parameters were examined: mortality; macroscopic and histological damage; hematocrit; plasma pH; acid-base balance; serum glucose; calcium, and amylase. RESULTS: Octreotide treatment had a striking effect on mortality: 8.3 versus 91.6% in the treatment and control groups, respectively (p < 0.001). Octreotide also ameliorated pancreatic edema and intestinal dilatation, and had significant beneficial effects on histopathological damage and the biochemical alterations which are associated with acute pancreatitis. CONCLUSIONS: Continuous intravenous octreotide infusion is a potentially efficacious therapeutic method for acute pancreatitis.

Acute Disease↗
PubMedDate not supplied

Negative bone scans in impending tibial stress fractures. A report of three cases.

Three highly motivated military recruits who presented with tibial pain on exertion are reported. Their initial bone scan assessments to rule out stress fracture were normal, and the recruits were returned to demanding training. One month later, because of persistent and increasing tibial pain, they were rescanned and focal activity representative of tibial stress fractures was found in each case. Until now it has been assumed that a negative bone scan ruled out a stress fracture unequivocally. Our reported cases show that bone pain may in fact precede scintigraphic evidence of a stress fracture. Persistent and increasing bone pain during demanding physical activity, even in the presence of a prior normal bone scan, may represent stress fracture and repeat bone scan may be indicated.

Humans↗
PubMedDate not supplied

Multiple stress fractures. A longitudinal study of a soldier with 13 lesions.

A highly motivated 18-year-old man continued vigorous military training in spite of the presence of 11 stress fractures and subsequently developed two additional stress fractures. Scintigraphy over 27 weeks illustrated simultaneous regression and progression in his individual multiple foci. When stress fracture foci were not in anatomic locations prone to evolve to gross fractures, healing occurred despite vigorous activities and pain.

Adolescent↗