The 'Modified U' technique: a refined method of Norplant removal

Norplant removal has been much more difficult for many physicians than might have been anticipated. Dr Untung Praptohardjo of Indonesia recently developed the "U" technique, speeding the time required to remove the six Norplant implants to an average of 7 minutes. In his technique, a unique oval-ring-tipped forceps with an internal diameter of 2.2 mm is used to reach through a 4-mm incision to firmly grasp each of the implants. The incision is made parallel to the implants between the lower tips of implants 3 and 4. The "U" technique requires grasping the implant within 4 mm to 5 mm of its tip. This preliminary paper describes the "Modified U" technique, which allows the physician who is removing the implants to grasp them anywhere along their shaft, not just near the tip. The Modified U technique involves the use of an improved ring-tipped forceps with a circular tip rather than the oval tip used in the "U" technique. This instrument, called Norgrasp, is a modification of the vas deferens fixation forceps used in the no-scalpel vasectomy (NSV) technique. In another adaptation of NSV instruments, an NSV dissecting forceps (a sharpened, curved hemostat) is used to free the implants from their tissue envelope and quickly deliver them through the skin incision. Using the Modified U technique, the time required to remove Norplant implants in 20 patients in the United States has ranged from 8 to 13 minutes. Improperly placed implants are readily removed with this technique. The Modified U technique requires a minimal incision and offers both the physician and the patient a speedy, positive removal.

Nebulized bacteriostatic saline as a cause of bronchitis

BACKGROUND

The purpose of this study was to determine whether nebulized bacteriostatic saline, which contains the preservative benzyl alcohol, is an irritant to the tracheobronchial mucosa in healthy adults.

METHODS

A randomized, double-blind, placebo-controlled study was conducted with 10 healthy adults who inhaled 3 mL of either bacteriostatic saline or saline placebo by nebulizer four times a day for 2 weeks. Pulmonary function tests and bronchoscopy with biopsy were performed immediately before and after the 2-week nebulization period.

RESULTS

Nine of 10 volunteers were compliant with the study protocol. Four of five volunteers who used nebulized bacteriostatic saline developed bronchitic symptoms and had bronchoscopic evidence of bronchitis. The fifth remained healthy. Four volunteers used nebulized saline (placebo). Two of these four became ill, one with a much more severe bronchitis than any of the bacteriostatic saline volunteers, and one with pharyngitis. Bronchoscopic biopsies showed a lymphocytic mucosal infiltrate in those who became ill while using nebulized bacteriostatic saline and a polymorphonuclear mucosal infiltrate in those who became ill while using nebulized saline placebo.

CONCLUSIONS

Nebulization of bacteriostatic saline, containing benzyl alcohol as its preservative, causes bronchitis in healthy adults. Even nebulization of sterile saline may be associated with bronchitis and pharyngitis. Physicians who prescribe nebulized medications must pay close attention to the bronchodilator diluent.

Vas deferens occlusion during no-scalpel vasectomy

The increasing popularity of the no-scalpel vasectomy (NSV) technique in the United States is driven by patient demand for surgical procedures presumed to be less invasive and by the somewhat lower complication rate of the NSV technique. The NSV technique addresses vasal delivery but not vasal occlusion. Intraluminal red-hot wire cautery with sheath closure over the inguinal end of the cut vas (Schmidt's method) has the lowest failure rate of all reasonable vas occlusion methods. The anatomical relationships of scrotal layers can be unclear during the NSV technique. Accurate identification of the sheath layer is critical to sheath interruption if this method of occlusion is to be used. Placement of an absorbable purse-string suture for sheath interruption during the NSV procedure is described. Special attention must be given to placement of one suture bite in the deep (posterior) sheath wall. The vasal occlusion technique described in this paper blends a refined method of vasal delivery (NSV) with the most effective method of vasal occlusion (cautery with sheath interruption).

Plasma pyridoxal phosphate in anxiety disorders

One hundred and eighty-nine subjects with either generalized anxiety disorder, panic disorder, or obsessive-compulsive disorder were evaluated for plasma pyridoxal phosphate (PLP) levels and compared with normal controls. There was no difference in plasma PLP levels between the anxiety disorder groups and normal controls. Low levels of plasma PLP were found in 42% of the controls. Our results suggest that previous reports of low PLP levels in psychiatric patients are unlikely to be significant in the etiology of the psychiatric disorders.

Pyridoxal 5'-phosphate related changes in retention of 1,25-dihydroxy vitamin D-receptor ligands in rat intestinal mucosa cell nuclei

After feeding rats a vitamin B-6-deficient diet, we observed a decrease in pyridoxal 5'-phosphate concentrations in intestinal mucosa cells to 32 and 48% of control in cytoplasm and cell nuclei, respectively. Correlation analysis suggested that there were two pyridoxal 5'-phosphate pools in the nuclei: a "mobile" pool (equivalent to about 5% the concentration of the cytoplasmic pyridoxal 5'-phosphate), and a "stable" pool, which was independent of cytoplasmic fluctuations of pyridoxal 5'-phosphate (about 9 pmol pyridoxal 5'-phosphate/mg DNA). Reduction in pyridoxal 5'-phosphate content in the cells of vitamin B-6-deficient animals was accompanied by a substantial increase in 1,25-dihydroxyvitamin D-receptor ligand concentration in the cell nuclei (76.6 +/- 19.7 vs 762 +/- 291 fmol/mg DNA, mean +/- SEM). The degree of 1,25-dihydroxyvitamin D accumulation in the nuclei appeared to be an exponential function of the "mobile" nuclear pyridoxal 5'-phosphate concentration. Semilogarithmic transformation of the data yielded a straight line, representing an inverse correlation between the cytoplasm-related nuclear pool of pyridoxal 5'-phosphate and the logarithm of the 1,25-dihydroxyvitamin D concentration in the nuclei (r = -0.95). These data suggest that pyridoxal 5'-phosphate may be related to 1,25-dihydroxyvitamin D retention in the nuclei, possibly through interaction of the pyridoxal 5'-phosphate with the vitamin D receptor protein in the nuclei.

Vitamin supplements: current controversies

Supplemental use of vitamins to prevent disease constitutes a major commercial enterprise in the United States. The efficacy of such use, or even the need for intakes above that which can be supplied by means of diet alone, has been the source of considerable controversy in the medical and scientific fields. Recently published data have given strong support to several of the claims for major benefits of disease prevention, including that of cancer, cardiovascular disease, carpal tunnel syndrome, and neural tube defects, to name just a few. The purported benefits for supplemental vitamin usage are discussed for these diseases, along with a call for a re-evaluation of the underlying philosophy of the Recommended Dietary Allowances, or consideration of their abolition, based on newly emerging data.

Accurate dosing of pediatric medications

Dosing of pediatric medications must be accurate. Combining constants in the usual calculation for amoxicillin dosing derives the Rule of Six (6 mg/lb per dose) for dosing. This rule generalizes to most pediatric antibiotics. The Decimal Move Rule (0.1 mL/lb per dose) can be used to dose many over-the-counter cough and cold remedies, bronchodilators, and iron preparations. A number of helpful hints to improve compliance and three comprehensive dosing tables are presented.

Treatment of myelodysplastic syndromes with daily oral idarubicin. A phase I-II study

BACKGROUND

Idarubicin, a new anthracycline analogue, is available in an oral preparation, and responses have been observed using relatively aggressive therapy in patients with myelodysplastic syndromes (MDS). The authors studied whether a chronic low-dose schedule would be effective but less myelotoxic.

METHODS

Forty-two patients with MDS received daily low-dose oral idarubicin in 5-week courses that included 3 weeks of treatment, followed by a 2-week rest period. Doses were escalated when possible after the second course, and each patient was to receive six courses.

RESULTS

Only one partial response was observed. Although no patient had fatal bone marrow toxicity, only eight patients received the full six courses, primarily because of myelosuppression.

CONCLUSIONS

This schedule of oral idarubicin is relatively safe but produces fewer responses than are reported with the high-dose pulse regimens.

Vitamin B-6 deficiency alters rat enterocyte calcium homeostasis but not duodenal transport

Isolated enterocytes were used as differential transporting cells to examine calcium homeostasis in control and vitamin B-6-deficient rats. Kinetic analysis of calcium fluxes, as well as biochemical determinations, indicated that enterocytes from control animals had high concentrations of cytosol ionized calcium (318.5 +/- 22.4 nmol/L) and a large pool of exchangeable calcium (2.72 nmol/mg protein, or 86% of total cell calcium). Vitamin B-6 deficiency resulted in a 44% reduction in total cellular calcium (1.71 +/- 0.24 vs. 3.07 +/- 0.29 nmol/mg protein), a 69% reduction in total exchangeable calcium (0.85 vs. 2.72 nmol/mg protein) and a 56% reduction in cytosol ionized calcium concentration (141.4 +/- 13.5 vs. 318.5 +/- 22.4 nmol/L). Calcium fluxes between all cellular compartments were markedly diminished as a result of vitamin B-6 deficiency. However, vitamin B-6 deficiency did not affect the basic morphological or functional features of the enterocytes, such as cell viability, cell volume, membrane permeability and protein content. Moreover, intestinal calcium transport in vivo was not affected during vitamin B-6 deficiency, perhaps due to the greater paracellular ion movement compensating for the lower transcellular transport.

Consumption of a dehydrated ration for 31 days at moderate altitudes: status of zinc, copper, and vitamin B-6

Intake of energy zinc, copper, and vitamin B-6 and indexes of zinc, copper and vitamin B-6 status were determined for eight men who consumed a high-carbohydrate dehydrated ration for 31 days of high activity at moderate altitudes (2,400 to 4,300 m). Data were collected 2 months before exposure (PRE), four times during the month at moderate altitudes (ALT), and 1 month after return (RET). Mean (+/- standard error) energy intake was 2,725 +/- 215, 3,430 +/- 79, and 3,370 +/- 215 kcal/day during PRE, ALT, and RET, respectively. Zinc and copper intakes averaged 10.6 +/- 1.6 and 1.0 +/- 0.1 mg/day during PRE and increased significantly to 16.9 +/- 0.7 and 3.5 +/- 0.1 mg/day during ALT; zinc and copper intakes were 15.5 +/- 1.6 and 1.9 +/- 0.3 mg/day for RET, respectively. Similarly, vitamin B-6 intake was significantly higher during ALT (PRE = 2.2 +/- 0.5 mg/day; ALT = 4.2 +/- 0.4 mg/day; and RET = 2.6 +/- 0.4 mg/day) as compared with PRE and RET. No significant changes were noted for plasma zinc, copper, or their related proteins or plasma or erythrocyte pyridoxal-5'-phosphate. Finally, no changes in urinary excretion of zinc were observed. The results indicate that dehydrated rations provide zinc, copper, and vitamin B-6 in amounts above the Recommended Dietary Allowances. Such diets may be consumed for at least 1 month without compromising status for these nutrients.

Effects of ascorbic acid and pyridoxine supplementation on oxalate metabolism in peritoneal dialysis patients

We studied the effect of vitamin C and B6 supplementation on oxalate metabolism in seven patients receiving chronic peritoneal dialysis therapy. The study was divided into three phases, each lasting 4 weeks. Plasma oxalate, total ascorbic acid, and pyridoxal-5'-phosphate (PLP) were measured at the end of each phase. Twenty-four-hour urinary excretion and dialysate removal rates of oxalate were also obtained. At the end of phase I (supplement-free period), plasma oxalate levels were markedly elevated at 47.6 +/- 7.1 mumol/L (437 +/- 66 micrograms/dL) (normal, 3.4 +/- 0.4 mumol/L [30.3 +/- 1.6 micrograms/dL]). Plasma total ascorbic acid levels were 62 +/- 6 mumol/L (1.0 +/- 0.1 mg/dL) (normal, 45 to 57 mumol/L [0.8 to 1.0 mg/dL]), while plasma PLP levels were markedly reduced to 24 +/- 5 nmol/L (normal, 40 to 80 nmol/L). Daily supplements of 0.57 mmol (100 mg) ascorbic acid orally (phase II) resulted in a 19% increase in the plasma oxalate levels to 57.8 +/- 6.1 mumol/L (520 +/- 55 micrograms/dL) (P less than 0.03), with a concomitant 60% increase in the plasma ascorbate levels (91 +/- 6 mumol/L [1.6 +/- 0.1 mg/dL], P less than 0.01). Plasma PLP values remained low. Finally, during phase III (0.57 mmol or 100 mg ascorbic acid plus 59.6 mumol or 10 mg pyridoxine HCI orally daily), plasma oxalate levels declined by 17% to 47.9 +/- 5.2 mumol/L (431 +/- 47 micrograms/dL) (P greater than 0.05 v phase II).(ABSTRACT TRUNCATED AT 250 WORDS)

Altitude retinopathy on Mount Everest, 1989

The authors studied prospectively the incidence of and risk factors for high altitude retinal hemorrhages among 14 members of the 1989 American Everest Expedition. All subjects had comprehensive eye examinations and fundus photography performed at sea level before the expedition and again at the Mt. Everest Base Camp after 6 weeks of exposure to altitudes between 5300 and 8200 meters. Asymptomatic intraretinal hemorrhages were found in five eyes of four climbers. An additional eye of one of these climbers had a central retinal vein occlusion with vitreous hemorrhage, which reduced visual acuity to counting fingers. Higher baseline intraocular pressure and use of nonsteroidal anti-inflammatory drugs were found to be significant risk factors for development of altitude retinopathy.

Consumption of a dehydrated ration for 31 days at moderate altitudes: energy intakes and physical performance

Energy intake, body weight, maximal work capacity, and measures of muscle strength and endurance were obtained from eight men who consumed a high-carbohydrate (CHO) dehydrated ration during a 31-day period of high activity at moderate altitudes. Data were collected 2 months before exposure to moderate altitudes (PRE), multiple times during the month's expedition at moderate altitudes (ALT), and after return from the expedition (RET). Work capacity per kilogram of body weight increased significantly from the PRE phase to the ALT phase. Mean energy intake averaged 2,354 +/- 71, 3,430 +/- 79, and 3,384 +/- 117 kcal/day during PRE, ALT, and RET, respectively; mean CHO intake during ALT was 595 +/- 13 g/day. Mean weight loss and reduction in body fat were significant: 1.9 +/- 0.9 kg and 18.9 +/- 10.1%, respectively. Energy deficits calculated from changes in body weight and composition during ALT ranged from 473 to 963 kcal/day, whereas the energy deficit estimated from the Harris-Benedict equation was only 194 kcal/day. The rigorous physical activity and exposure to moderate altitudes necessitated a high energy intake, approximating 3,800 kcal/day. The results indicate that physical performance and nutritional status are maintained when a high-CHO diet, consisting primarily of commercially available dehydrated foods, is consumed over a 31-day period of rigorous activity. However, weight loss and gastrointestinal distress were noted. These events might be minimized when a dehydrated ration is consumed, if dietary fat is substituted for some of the CHO.

Ascorbic acid supplements in patients receiving chronic peritoneal dialysis

Ascorbic acid supplements are commonly prescribed to patients with end-stage renal disease receiving peritoneal dialysis. To establish the need for ascorbic acid supplements, we evaluated seven chronic peritoneal dialysis patients during a supplement-free (phase I) period, and while receiving oral ascorbic acid (0.57 mmol/d [100 mg/d]) (phase II). Because of a proposed interaction with vitamin B6, patients were additionally supplemented with pyridoxine HCl (59.6 mumol/d [10 mg/d]) (phase III). Plasma levels and dialysate removal rates of total ascorbic acid and plasma pyridoxal-5-phosphate (PLP) were measured at the end of each phase. During phase I, plasma ascorbic acid levels (normal, 45 to 57 mumol/L [0.8 to 1.0 mg/dL]) declined slightly from 74 +/- 11 mumol/L (1.3 +/- 0.2 mg/dL) to 62 +/- 11 mumol/L (1.1 +/- 0.2 mg/dL) (P less than 0.02) at the end of the third week, and then remained stable to the end of the fourth week. Plasma ascorbic acid levels were no different in patients with or without residual renal function. With the addition of vitamin C supplements, plasma ascorbic acid levels increased by 45% of the baseline value at the end of phases II (P less than 0.001). The dialysate removal rate of ascorbic acid was 0.28 +/- 0.03 mmol/d (50 +/- 6 mg/d) at the end of phase I, and increased by 57% of the baseline value at the end of phases II (P less than 0.001). However, the peritoneal clearance of ascorbic acid remained unchanged during all phases the study. Pyridoxine depletion or repletion had no effect on plasma ascorbic acid levels (P greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Extremely low serum pyridoxal 5'-phosphate in children with familial hypophosphatemic rickets

The apparent vitamin B-6 status of 31 children with familial hypophosphatemic rickets (FHR) was determined. All children had alkaline phosphatase activity that was high-normal to elevated for their ages. A sensitive assay for pyridoxal 5'-phosphate (PLP) indicated that 15 of the 31 children had an undetectable (less than 0.2 nmol/L) concentration of the vitamer--the lowest values yet reported in human serum. The 16 remaining children had concentrations of the vitamer so low that they indicated a potential severe vitamin B-6 deficiency. However, none of the children had ever presented with any of the classical vitamin B-6-deficiency symptoms. Treatment of three additional FHR children with 100 mg pyridoxine.HCl/d resulted in a moderate and transient elevation of their serum PLP concentrations, a dramatic elevation of their erythrocyte PLP concentrations, and no improvement in clinical condition. Serum or plasma PLP concentrations are an inappropriate index for determining vitamin B-6 status in people with FHR and perhaps in others with elevated alkaline phosphatase activity.