Resistance to glutathione depletion in diabetic and non-diabetic human erythrocytes in-vitro

We have investigated the resistance of erythrocytes from diabetics and non-diabetics to glutathione depletion caused by p-benzoquinone, 1-chloro-2,4-dinitrobenzene (CDNB), diethyl maleate and 4-aminophenol. Incubation of erythrocytes with 4-aminophenol (2 mM) caused a precipitous reduction (>80%) in cellular glutathione levels although there was no significant difference between 4-aminophenol-mediated glutathione depletion in the diabetic and non-diabetic cells. p-Benzoquinone and CDNB were both associated with a less severe initial reduction in glutathione levels (>50% at 30 min) although p-benzoquinone caused greater depletion (P < 0.001) at 4.5 h (21.1 +/- 3.1%, non-diabetic; 20.0 +/- 1.0%, diabetic) compared with CDNB (49.2 +/- 2.2%, non-diabetic; 51.3 +/- 1.1% diabetic). Although there was no significant difference between the two types of cell in terms of level of depletion, administration of diethyl maleate caused a significant reduction in glutathione levels at 30 min (P < 0.0005), 3.5 h (P < 0.05) and 4.5 h (P < 0.05) in erythrocytes from diabetic man compared with those from non-diabetic man. Co-administration of buthionine sulphoximine (20 mM) and 4-aminophenol (1 mM) also led to a significant reduction in glutathione levels in diabetic cells at 30 min (P < 0.05), 3.5 h (P < 0.02) and 4.5 h (P < 0.007) compared with those in non-diabetic cells. The observations that diabetic red cells' resistance to depletion was similar to that of nondiabetic cells for three of the four depletors, and that the combination of 4-aminophenol and buthionine sulphoximine-mediated inhibition of glutathione synthesis was required to illustrate differences suggests that diabetic complications might be a result of the long-term effect of small deficiencies in oxidative self-defence mechanisms such as glutathione.     

Identification of urinary metabolites of isoprene in rats and comparison with mouse urinary metabolites.

Isoprene, a major commodity chemical used in production of polyisoprene elastomers, has been shown to be carcinogenic in rodents. Similar to findings for the structurally related compound butadiene, mice are more susceptible than rats to isoprene-induced toxicity and carcinogenicity. Although differences in uptake, and disposition of isoprene in rats and mice have been described, its in vivo biotransformation products have not been characterized in either species. The purpose of these studies was to identify the urinary metabolites of isoprene in Fischer 344 rats and compare these metabolites with those formed in male B6C3F1 mice. After i.p. administration of 64 mg [14C]isoprene/kg to rats and mice, isoprene was excreted unchanged in breath ( approximately 50%) or as urinary metabolites ( approximately 32%). In rats isoprene was primarily excreted in urine as 2-hydroxy-2-methyl-3-butenoic acid (53%), 2-methyl-3-buten-1,2-diol (23%), and the C-1 glucuronide conjugate of 2-methyl-3-buten-1,2-diol (13%). These metabolites are consistent with preferential oxidation of isoprene's methyl-substituted vinyl group. No oxidation of the unsubstituted vinyl group was observed. In addition to the isoprene metabolites found in rat urine, mouse urine contained numerous other isoprene metabolites with a larger percentage (25%) of total urinary radioactivity associated with an unidentified, polar fraction than in the rat (7%). Unlike butadiene, there was no evidence that glutathione conjugation played a significant role in the metabolism of isoprene in rats. Because of the unidentified metabolites in mouse urine, involvement of glutathione in the metabolism of isoprene in mice cannot be delineated.     

Endoscopic Treatment of Vesicoureteral Reflux with Collagen: Preliminary Report and Cost Analysis

Purpose

We determined therapeutic and operative cost efficacy of endoscopic collagen injection for vesicoureteral reflux.

Materials and Methods

We performed a multicenter study of 10 male and 23 female sequential patients (45 renal units) with vesicoureteral reflux and a surgical indication. Patients were skin tested with collagen and when negative, they underwent endoscopic injection. Renal ultrasound/ cystography was done 3 months after treatment. Cost analysis was performed at 1 institution.

Results

Reflux was grade I in 2 renal units, II in 18, III in 15 and IV in 10. The majority of cases were single systems with primary reflux. We performed 1 treatment in 32 renal units, 2 in 6, 3 in 6 and 4 in 1. Cure was evident in 31 of 38 renal units (81.6 percent) and 21 of 27 patients (78 percent) 3 months after the last injection. Patient morbidity was minimal. Operative cost per renal unit was $1,599.68 for collagen injection and $9,144.47 for reimplantation.

Conclusions

Endoscopic injection of collagen is effective treatment for vesicoureteral reflux. Furthermore, it causes minimal morbidity and may effect cost savings in health care management.     

Future family physicians get early community contact in Morehouse curriculum

The pre-clinical curriculum of the Morehouse School of Medicine is unique in several ways. One of the ways in which this curriculum is unique is the manner in which it has involved practicing physicians in the education of medical students during their first two years of medical school. Throughout the country, many physicians have expressed an interest in this involvement of community physicians in the teaching of medical students during what might be their most impressionable period of development. The article which follows describes concisely the development of Community Medicine and Family Practice at the Morehouse School of Medicine, highlighting the issues which relate to the role of community physicians in the teaching of medical students during the pre-clinical years. It is the contention of Morehouse officials that the involvement of practicing physicians in the early education of medical students is very important and that it does not necessitate a compromise of the basic science education which is taking place at this time.     

Seizures and civilian head injuries

Although several studies have reported on the risk of "early seizures" (seizures occurring within 7 days following a head injury), the reported proportions of patients experiencing these seizures vary from 1.4 to 15%. This wide divergence may be due to problems with methodology such as case selection and definitions of head injury and early seizures. In a series of 702 patients admitted with a head injury to Cook County Hospital (CCH), Chicago, Illinois, 29 (4.1%) had early seizures. This proportion is twice as high as one previously reported in a comparable series. This may reflect an actual difference between the two series or a case selection bias serving to elevate the proportion of patients with early seizures at CCH.     

Dynamic radionuclide imaging as a means of evaluating vascular perfusion of the upper extremity: a preliminary report

Vascular competence in the upper extremities of 44 patients was evaluated by three-phase bone scans consisting of rapid sequence dynamic radionuclide imaging (DRI), an immediate postinjection "blood pool" image, and a 3- to 4-hour delayed image. Findings were correlated with definitive anatomy determined by arteriography, operative findings, or both, in 50 extremities. DRI provided the correct diagnosis in all but four extremities (92%). Limited resolution precluded precise anatomic definition of aneurysms in three limbs and of digital artery occlusion, with adequate collateral circulation in the fourth limb. The greatest value of DRI was its provision of quantitative information about relative blood flow and preferential perfusion in every instance. We believe DRI to be a useful adjunct to preoperative and postoperative assessment of arterial perfusion.     

Information content of dentists' Yellow Pages advertising

Content analysis was performed on 1,007 Yellow Pages dental display ads to investigate whether such advertisements include the information important to consumers. The authors found a significant information gap between what consumers considered important when selecting a dentist and the information provided in the advertisements. The research was supported in part by a grant to Caroline Fisher from the American Marketing Association.     

Preoperative and postoperative voice analysis of uvulopalatopharyngoplasty patients.

While clinical studies almost universally report few speech and voice complications from uvulopalatopharyngoplasty, there is a paucity of prospective studies concerned with formal acoustic and perceptual evaluation of these patients. This study compares preoperative and postoperative recordings of 32 uvulopalatopharyngoplasty patients. Fast Fourier Transform analyses were made of both long-term spectra of a reading passage and the resonant characteristics of three vowels. Fundamental frequency and reading time were quantified. Polysomnographic studies of these patients were also compared. Finally, listener judgments of "better voice" were made on preoperative and postoperative pairs of the same patients performing a reading task. While the polysomnographic data demonstrated statistically significant improvement in the physical condition of the patients, no perceptual or acoustic measure of voice or speech was significant when preoperative and postoperative scores were compared.