Effects of short-term growth hormone therapy in rats undergoing 75% small intestinal resection.

Thirty 250-g male rats underwent 75% small intestinal resection and received s.c. injections of water [short gut (SG)-control], human growth hormone (hGH) at 0.1 mg/kg/dose [SG-low-dose (LD) GH], or hGH at 1.0 mg/kg/dose [SG-high-dose (HD) GH] every other day for 28 days. Ten additional rats underwent sham operation and received water injections (sham control). After 28 days, SG-control and SG-LDGH rats weighed significantly less than the sham control group; the mean weight of the SG-HDGH group was not different from other groups. Weight per centimeter of the distal ileum was greater in all SG groups compared to the sham control group, and was greater in the SG-HDGH than in the SG-control group. Mean mucosal height of the distal ileum was greater in both SG groups receiving GH than in sham controls. No differences in ileal mucosal DNA content or ileal insulin-like growth factor-1 (IGF-1) content were identified between groups. Mucosal sucrase activity was not increased in hGH-treated rats. Serum calcium and phosphorus concentrations were higher in SG-HDGH rats than in SG-control animals. HDGH increased body weight, distal ileal weight/cm, and mucosal height in rats undergoing 75% small bowel resection. A trend toward normalization of serum calcium, phosphorus, and plasma IGF-1 concentrations was also observed. Further longer-term studies are indicated to learn if GH has a beneficial effect upon gut growth and function in the SG syndrome.

Long duration local anesthesia with lecithin-coated microdroplets of methoxyflurane: studies with rat skin.

Lecithin-coated microdroplets of methoxyflurane (MOF) are shown to produce local anesthesia of three- to six-day duration in the skin with a single intradermal injection in rats. Anesthesia was quantitated by elevation of the threshold (milliampere) for shock vocalization with intradermal electrodes. Intradermal injection of 0.1 ml 0.5% MOF gave moderate (2.1 mA) anesthesia of approximately three-day duration for a 10-12-mm diameter area, with no damage to the tissue. Higher concentrations gave six-day duration anesthesia at very high level (7 to 12 mA) anesthesia of three- to five-day duration with some damage to the tissue. At 4.4% MOF, ulcers formed in the center of the injection site with maximal dimensions of 1.3 mm (11-13% of the site diameter). Phenol, a widely used neurolytic agent, was tested as a control in the same concentration range. Phenol at 4.4% gave very high level (8 mA) anesthesia for longer than seven-day duration and caused formation of ulcers with maximal dimensions of 3.8 mm (31-38% of the site diameter). Analysis showed that MOF produced less damage than phenol for any given degree of anesthesia. Systemic toxicity and pharmacokinetic data are also presented. Phenol produced a hypothermic reaction and behavioral changes, whereas MOF was without systemic effect. The plasma concentrations of phenol were four to five times greater than those of MOF. These results suggest that MOF may have clinical advantages over phenol.

Argyrophilic nucleolar organizer regions in Wilms' tumors and related lesions: a histologic and chromosomal correlation.

The argyrophilic nucleolar organizer regions (AgNORs) have been extensively investigated in different neoplasms, and their increased number has been frequently linked to aggressive tumor behavior. To evaluate this association, 22 specimens from 21 patients with Wilms' tumors and related lesions were stained by the AgNOR silver-staining technique in formalin-fixed, paraffin-embedded tissue. The aim of the study was to assess the significance of AgNOR count independently or in relation to histology in predicting the behavior of these neoplasms. Eleven nonneoplastic pediatric kidneys were used as controls. The controls had a range of 1.55 to 2.26 AgNOR/nucleus with a mean +/- SD of 1.91 +/- 0.22. The tumors showed a range of 1.25 to 2.86 AgNOR/nucleus with a mean +/- SD of 2.10 +/- 0.38 with obvious overlap between tumors and controls. The two unfavorable histology Wilms' tumors and the malignant rhabdoid tumor showed no increase in the number of AgNOR (1.66, 2.04, and 2.05, respectively). We further quantitated the nucleolar organizer regions (NOR) in metaphase spreads of three of the neoplasms, compared those with the patients' peripheral blood, and showed no difference in NOR numbers except for an occasional decrease in G-group NORs in the tumor cells. Tumors that had metaphase NOR counts of 6 to 9/nucleus had a mean interphase AgNOR count of less than 2.5. These results suggest that quantitative analysis of AgNORs in Wilms' tumors and related lesions is not a reliable predictor of aggressive tumor behavior. The discrepancy between metaphase and interphase NOR counts indicates that AgNOR counts are merely the reflection of the spatial arrangement of NOR-bearing chromosomes.