Thallium/technetium subtraction scanning for primary hyperparathyroidism: scan sensitivity and effect on operative time.

Over a ten-year period 26 patients were evaluated by the authors for elevated serum calcium and parathormone levels. All patients were clinically asymptomatic and were referred for parathyroid evaluation following a diagnosis of hypercalcemia made on routine SMA-12 studies. Twenty-four patients had positive thallium/technetium subtraction studies; two were suggestive of bilateral adenomata, one of which was confirmed at surgery. In two patients both thallium/technetium and technetium sestamibi scanning studies were negative. These patients were managed medically without surgical exploration. In all operative cases the patients remained normocalcemic during a six-month follow-up period. Operative times in all cases were less than one hour.

Non-smoking policies, tobacco education, and smoking cessation programmes in facilities serving the elderly in Michigan, United States.

OBJECTIVE: To determine the extent of and impetus for smoke-free policies in facilities serving Michigan's elderly, and the extent of tobacco education and smoking cessation programmes for elders and staff of these facilities. DESIGN: Telephone survey in February 1997 of three types of facilities serving Michigan's elderly population. SUBJECTS: Area Agencies on Aging (n = 12), Councils and Commissions on Aging (n = 31), and senior centres (n = 98) located in Michigan, USA. MAIN OUTCOME MEASURES: Prevalence of smoke-free policies, tobacco education, and smoking cessation programmes in facilities serving the elderly. RESULTS: 99% (95% confidence interval (CI) = 97% to 100%) of 141 facilities surveyed have an indoor smoke-free policy. Eighty-five per cent (95% CI = 79% to 91%) of these policies prohibit all smoking inside the facility. Forty-five per cent (95% CI = 37% to 54%) cited a law as requiring the smoke-free policy, whereas 38% (95% CI = 30% to 46%) indicated the policy was adopted voluntarily for health reasons. Forty-two per cent (95% CI = 34% to 50%) of the facilities provided some education on the dangers of tobacco, while 11% (95% CI = 6% to 16%) arranged smoking cessation programmes for staff or elders. CONCLUSIONS: In Michigan, a very high percentage of non-institutional facilities serving the elderly have smoke-free policies, which appear to increase participation at these facilities. Tobacco education programmes are provided in less than half the facilities, and very few arrange smoking cessation programmes for elders or staff.

An unusual cause of dysphagia following total laryngectomy.

A case of dysphagia following wide-field total laryngectomy with excision of the overlying skin is presented. Initial investigation as to the cause of the dysphagia proved fruitless. Mechanical compression of an adequate-sized neopharynx by the "band-like effect" created by the skin closure was hypothesized to be the etiology of the dysphagia. Release of the scar contracture and resurfacing with a pectoralis major myocutaneous flap reestablished an adequate-sized hypopharynx and normal deglutition.

A pH modifier site regulates activity of the Na+:HCO3- cotransporter in basolateral membranes of kidney proximal tubules.

HCO3- exit across the basolateral membrane of the kidney proximal tubule cell is mediated via an electrogenic Na+:HCO3- cotransporter. In these experiments, we have studied the effect of internal pH on the activity of the Na+:HCO3- cotransport system in basolateral membrane vesicles isolated from rabbit renal cortex. Equilibrium thermodynamics predicts that in the presence of constant intravesicular concentration of Na+, an increasing concentration of HCO3- will be associated with an increasing driving force for Na+:HCO3- cotransport across the vesicles. Our experimental approach was to preequilibrate the membrane vesicles with 1 mM 22Na+ at pHi 6.8-8.0 and known concentrations of HCO3-. The vesicles were diluted 1:100 into Na(+)-free solution at pH 7.4 and the net flux of 22Na+ was assayed over 5 s. The results demonstrate that the net flux of Na+ was significantly higher at pHi 7.2 than pHi 8.0 despite much higher [HCO3-] at pHi 8.0. This suggests that an internal pH-sensitive site regulates the activity of the Na+:HCO3- cotransporter. This modifier site inhibits the cotransporter at alkaline pH despite significant base concentration and is maximally functional around physiologic pH. The combination of modifier sites on the luminal Na+/H+ exchanger and the basolateral Na+:HCO3- cotransporter should help maintain intracellular pH in a narrow range with changes in extracellular pH.

Cation specificity and modes of the Na+:CO3(2-):HCO3- cotransporter in renal basolateral membrane vesicles.

The cation specificity and possible exchange modes of the Na+:CO3(2-):HCO3- cotransporter were evaluated by use of basolateral membrane vesicles isolated from rabbit renal cortex. External Li+ inhibited HCO3- gradient-stimulated 22Na uptake, indicating that Li+ interacts with the Na+:CO3(2-):HCO3- cotransporter. No interaction with K+, choline, Rb+, Cs+, or NH4+ could be similarly detected. Imposing an outward Li+ gradient caused quenching of acridine orange fluorescence in the presence but not in the absence of HCO3-, suggesting that Li+:base cotransport takes place via the Na+:CO3(2-):HCO3- cotransporter. Imposing an outward gradient of unlabeled Na+ stimulated the initial rate of 22Na uptake and induced its transient uphill accumulation, indicating Na(+)-Na+ exchange. Na(+)-Na+ exchange was observed in the presence but not in the absence of HCO3- and was inhibited by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), suggesting that it occurs via the Na+:CO3(2-):HCO3- cotransporter. Similarly, an outward Li+ gradient stimulated uphill 22Na accumulation, indicating Na(+)-Li+ exchange. Na(+)-Li+ exchange was observed in the presence but not in the absence of HCO3-, and was inhibited by DIDS, suggesting that it also occurs via the Na+:CO3(2-):HCO3- cotransporter. Both Na(+)-Na+ and Li(+)-Na+ exchange modes were sensitive to inhibition by harmaline but not by amiloride. We conclude that Li+ is an alternative substrate for the renal Na+:CO3(2-):HCO3- cotransporter. Transport modes of the system include cation:base cotransport and HCO3-dependent cation-cation exchange.

Potassium depletion increases luminal Na+/H+ exchange and basolateral Na+:CO3=:HCO3- cotransport in rat renal cortex.

Most HCO3- reabsorption in proximal tubules occurs via electroneutral Na+/H+ exchange in brush border membranes (BBMS) and electrogenic Na+:CO3=:HCO3- cotransport in basolateral membranes (BLMS). Since potassium depletion (KD) increases HCO3- reabsorption in proximal tubules, we evaluated these transport systems using BBM and BLM vesicles, respectively, from control (C) and KD rats. Feeding rats a potassium deficient diet for 3-4 wk resulted in lower plasma [K+] (2.94 mEq/liter, KD vs. 4.47 C), and higher arterial pH (7.51 KD vs. 7.39 C). KD rats gained less weight than C but had higher renal cortical weight. Influx of 1 mM 22Na+ at 5 s (pHo 7.5, pHi 6.0, 10% CO2, 90% N2) into BLM vesicles was 44% higher in the KD group compared to C with no difference in equilibrium uptake. The increment in Na+ influx in the KD group was DIDS sensitive, suggesting that Na+:CO3=:HCO3- cotransport accounted for the observed differences. Kinetic analysis of Na+ influx showed a Km of 8.2 mM in KD vs. 7.6 mM in C and Vmax of 278 nmol/min/mg protein in KD vs. 177 nmol/min/mg protein in C. Influx of 1 mM 22Na+ at 5 s (pHo 7.5, pHi 6.0) into BBM vesicles was 34% higher in the KD group compared to C with no difference in equilibrium uptake. The increment in Na+ influx in the KD group was amiloride sensitive, suggesting that Na+/H+ exchange was responsible for the observed differences. Kinetic analysis of Na+ influx showed a Km of 6.2 mM in KD vs. 7.1 mM in C and Vmax of 209 nmol/min/mg protein in KD vs. 144 nmol/min/mg protein in C. Uptakes of Na(+)-dependent [3H]glucose into BBM and [14C]succinate into BLM vesicles were not different in KD and C groups, suggesting that the Na+/H+ exchanger and Na+:CO3=:HCO3- cotransporter activities were specifically altered in KD. We conclude that adaptive increases in basolateral Na+:CO3=:HCO3- cotransport and luminal Na+H+ exchange are likely responsible for increased HCO3- reabsorption in proximal tubules of KD animals.

Prophylactic submental skin incision after tight mucosal closure in total laryngectomy.

In this article, we will discuss prophylactic submental skin incision-performed after tight mucosal closure-in total laryngectomy; we will suggest means of avoiding incisional breakdown and pharyngocutaneous fistula.

Acute back pain: a control-group comparison of behavioral vs traditional management methods.

Back-pain patients with onset in the preceding 1-10 days and comparable on a back examination were randomly assigned to traditional management (A regimen) and behavioral treatment methods (B regimen). Patients were compared at 6 weeks and 9-12 months on a set of "Sick/Well" scores derived from patient reported vocational status (V), health-care utilization (HCU), claimed impairment (CI), and pain drawings (D) and on two measures of activity level. No differences were found at 6 weeks, but at 9-12 months, A-group S's were more "sick." No A/B differences were found on activity-level measures. Group A S's showed significant increases in claimed impairment from preonset to follow-up, whereas Group B S's had returned at follow-up to preonset levels.

Idiopathic malignant hyperthermia. Review and report of a case.

All physicians performing surgery while the patient is under general anesthesia must be aware of the existence of idiopathic malignant hyperthermia. A young adult had a malignant hyperthermic reaction despite four prior uneventful administrations of general anesthetics. To my knowledge, this is the first report of a patient who survived following a hyperthermic reaction, having sustained considerable residual brain damage. There is a great need for continuous body-temperature monitoring during general anesthesia.