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Biomedical subjects

M S Allen

Publications and source records attributed to M S Allen.

At least 55 records · Page 3Linked to original sources
PubMed2000

Cholecystokinin mediates depression of feed intake in dairy cattle fed high fat diets.

Two experiments were conducted to investigate the effects of 1) different concentrations of dietary fat and 2) i.v. administration of a cholecystokinin receptor antagonist (MK-329) on feed intake and plasma concentrations of hormones and metabolites in dairy cattle. In Experiment 1, 4 lactating Holstein cows were used in a 4 x 4 Latin square design. Treatments were diets with 1) no fat added, 2) 30 g fat/kg feed (calcium salts of long-chain fatty acids as fat supplement), 3) 60 g fat/kg, and 4) 90 g fat/kg added. Cows were fed once daily a diet of concentrate, corn silage, alfalfa haylage, and alfalfa pellets. Dry matter intake decreased linearly with increasing concentrations of dietary fat (P < 0.0001). Overall plasma concentrations of nonesterified fatty acids (P < 0.0001), triacylglycerol (P < 0.0006), and cholecystokinin (P < 0.02), increased linearly with each level of dietary fat, but there was a linear decrease in plasma insulin (P < 0.0008). In Experiment 2, 4 nonpregnant and nonlactating Holstein heifers were used in a cross-over design in a 2 x 2 factorial arrangement of treatments. Treatments were diet (fatty acids, 27 g/kg vs 103 g/kg diet dry matter) and i.v. injections (MK-329 vs vehicle). Heifers were fed once daily a total mixed ration of corn silage, cracked corn and soybean meal with or without fat supplement. Diets were switched by period and either MK-329 (70 microg/kg body weight) or its vehicle was injected i.v. at 2 hr postfeeding. Daily dry matter intake was decreased by feeding the high fat diet (P < 0.02) but was not affected by injections. Injection of MK-329, however, increased dry matter intake by 92% in heifers fed the high fat diet during the first 2 hr postinjection compared to vehicle injection. Plasma pancreatic polypeptide concentration was increased by the high fat diet at 2 hr postfeeding (P < 0.02) but was lowered by MK-329 at 1 hr postinjection (P < 0.001). Plasma insulin was lowered by the high fat diet (P < 0.01) but was not affected by injections. The elevated plasma cholecystokinin concentration may have mediated depressed feed intake of dairy cattle fed the high fat diets.

Animals↗
PubMed2000

Adenosine kinase of Arabidopsis. Kinetic properties and gene expression.

To assess the functional significance of adenosine salvage in plants, the cDNAs and genes encoding two isoforms of adenosine kinase (ADK) were isolated from Arabidopsis. The ADK1- and ADK2-coding sequences are very similar, sharing 92% and 89% amino acid and nucleotide identity, respectively. Each cDNA was overexpressed in Escherichia coli, and the catalytic activity of each isoform was determined. Both ADKs had similar catalytic properties with a K(m) and V(max)/K(m) for adenosine of 0.3 to 0.5 microM and 5.4 to 22 L min(-1) mg(-1) protein, respectively. The K(m) and V(max)/K(m) for the cytokinin riboside N(6)(isopentenyl) adenosine are 3 to 5 microM and 0.021 to 0.14 L min(-1) mg(-1) protein, respectively, suggesting that adenosine is the preferred substrate for both ADK isoforms. In Arabidopsis plants, both ADK genes are expressed constitutively, with the highest steady-state mRNA levels being found in stem and root. ADK1 transcript levels were generally higher than those of ADK2. ADK enzyme activity reflected relative ADK protein levels seen in immunoblots for leaves, flowers, and stems but only poorly so for roots, siliques, and dry seeds. The catalytic properties, tissue accumulation, and expression levels of these ADKs suggest that they play a key metabolic role in the salvage synthesis of adenylates and methyl recycling in Arabidopsis. They may also contribute to cytokinin interconversion.

Adenosine↗
PubMed2000

Brown midrib-3 corn silage improves digestion but not performance of growing beef steers.

The brown midrib-3 (bm3) gene mutation has been incorporated into corn plants to potentially improve fiber digestibility. The objectives of this study were to determine the effect of bm3 corn silage on digestion and performance of growing beef steers and to determine whether limiting intake would further enhance fiber digestibility of bm3 corn silage. A bm3 hybrid and its isogeneic normal counterpart were harvested at three-quarters kernel milk line. Neutral detergent fiber, ADF, and ADL were 4.5, 6.9, and 1.9 units lower, respectively, and DM was 5.4 units higher for bm3 than for normal silage. In Trial 1, eight ruminally fistulated Angus crossbred steers (224 +/- 24 kg) were randomly assigned to a 2 x 2 factorial arrangement of treatments in a replicated 4 x 4 Latin square design. Steers had ad libitum feed access or were restricted to 80% of ad libitum intake of diets containing 86% normal corn silage (Control) or bm3 corn silage (BMCS). The remainder of the diets consisted of soybean meal, urea, monensin, vitamins, and minerals. Dry matter intake was greater (P < 0.01) for steers offered ad libitum access to BMCS than for those with ad libitum access to the Control diet. The BMCS treatment resulted in improved (P < 0.05) apparent total-tract digestibility of DM, OM, NDF, and ADF. Mean concentration of total VFA and molar proportions of acetate were increased (P < 0.05) by feeding BMCS. There tended to be a DMI x hybrid interaction (P = 0.16) for apparent total-tract digestibility of NDF. When diets were offered ad libitum, BMCS increased NDF digestibility by 10.5 percentage units compared with Control, but, when DMI was limited, BMCS increased NDF digestibility by 15.8 percentage units. In Trial 2, 128 steer contemporaries of those used in Trial 1 (245 +/- 13 kg) were offered ad libitum access to BMCS or Control diets as used in Trial 1. After a 112-d treatment period, concentrate in the diet was increased, and all steers were fed a common finishing diet. During the 112-d treatment period, steers receiving BMCS consumed 0.45 kg more DM/d (P < 0.05) and had similar ADG (P > 0.10), compared with those steers receiving the Control silage. This resulted in poorer (P < 0.01) feed efficiency for steers receiving BMCS. Finishing phase and overall performance of the steers was not different (P > 0.10) due to treatment. Although feeding BMCS in growth-phase diets resulted in increased daily DMI and improved digestibility of DM and fiber, it did not result in improved steer feedlot ADG compared with Control silage.

Animal Feed↗
PubMed2000

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 1. Feeding behavior and nutrient utilization.

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on feeding behavior, dry matter intake (DMI), and energy utilization were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). Both low NDF diets and bm3 corn silage treatments increased DMI and milk yield. However, an interaction between corn silage treatment and dietary NDF content was observed for meal size and for interval between meals, implying that different mechanisms regulating DMI dominate depending on the fermentation characteristics of diets. The bm3 treatment depressed milk fat concentration when fed in a low NDF diet. The bm3 corn silage increased solids-corrected milk yield, but did not affect daily body weight gain compared with control, whereas low NDF diets increased daily body weight gain, but did not affect solids-corrected milk yield compared to high NDF diets. Both bm3 treatments and low NDF diets reduced ruminal pH, but low NDF treatments increased fluctuation of ruminal pH and bm3 treatments did not. Feeding bm3 corn silage increased the energy utilized for milk production, possibly because of a consistent supply of metabolic fuels from the rumen. The beneficial effects of bm3 corn silage on productivity of lactating cows were greater for the cows fed a high NDF diet.

Animals↗
PubMed2000

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 2. Chewing activities.

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on chewing activities were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). The NDF digestibility estimated by 30-h in vitro fermentation was higher for bm3 corn silage by 9.4 units (55.9 vs. 46.5%). Feeding behavior of animals and ruminal pH were monitored continuously for 4 d in each period by a computerized data acquisition system. Ruminal digesta were evacuated twice per period to determine the ruminal NDF pool and its turnover rate. There was no effect of NDF digestibility on total chewing time either per day or per kilogram of NDF intake, or on ruminating time either per day or per kilogram of NDF intake. Although bm3 treatments increased the turnover rate of NDF in the rumen, they increased dry matter intake and had no effect on ruminal NDF pool size. Total chewing time and ruminating time per day were related positively to NDF intake and ruminal NDF pool size, but were not related to ruminal turnover rate of NDF. These results provide no evidence that enhanced NDF digestibility decreases the physical effectiveness of NDF of corn silage.

Animals↗
PubMed2000

Effects of brown midrib 3 mutation in corn silage on productivity of dairy cows fed two concentrations of dietary neutral detergent fiber: 3. Digestibility and microbial efficiency.

The effects of digestibility of corn silage neutral detergent fiber (NDF) and dietary NDF content on ruminal digestion kinetics, site of nutrient digestion, and microbial N production efficiency were evaluated with eight multiparous high producing dairy cows in a duplicated 4 x 4 Latin square design with 21-d periods. Experimental diets contained corn silage from a brown midrib (bm3) hybrid or its isogenic normal control at two concentrations of dietary NDF (29 and 38%). The NDF digestibility estimated by a 30-h in vitro fermentation was higher for bm3 corn silage by 9.4 units (55.9 vs. 46.5%). Neither ruminal nor total tract NDF digestibility was affected by corn silage treatment. The bm3 corn silage diet decreased starch digestibility in the rumen and in the total tract, but increased postruminal starch digestibility compared with control diet. The bm3 corn silage diets increased microbial N flow to the duodenum and tended to decrease ruminal ammonia concentration. Microbial efficiency was greater for cows fed bm3 corn silage in spite of lower ruminal pH. Higher efficiency of microbial nitrogen production might be attributed to faster passage rate of NDF for cows fed bm3 corn silage compared with those fed control corn silage. Higher in vitro NDF digestibility might predict enhanced NDF fragility and ease of NDF hydrolysis in vivo. Enhanced in vitro NDF digestibility does not necessarily result in increased NDF digestibility either in the rumen or in the total tract, but possibly increases rate of passage and DMI, improving efficiency of microbial N production.

Animal Feed↗
PubMed2000

Effects of diet on short-term regulation of feed intake by lactating dairy cattle.

Physical and chemical characteristics of dietary ingredients and their interactions can have a large effect on dry matter intake (DMI) of lactating cows. Physical limitations caused by distension of the reticulo-rumen or other compartments of the gastrointestinal tract often limit DMI of high producing cows or cows fed high forage diets. Fermentation acids also limit DMI from a combination of increased osmolality in the reticulo-rumen and specific effects of propionate, although the mechanisms are not clear. The specific physical and chemical characteristics of diets that can affect DMI include fiber content, ease of hydrolysis of starch and fiber, particle size, particle fragility, silage fermentation products, concentration and characteristics of fat, and the amount and ruminal degradation of protein. Site of starch digestion affects the form of metabolic fuel absorbed, which can affect DMI because absorbed propionate appears to be more hypophagic than lactate or absorbed glucose. Dry matter intake is likely determined by integration of signals in brain satiety centers. Difficulty in measurement and extensive interactions among the variables make it challenging to account for dietary effects when predicting DMI. However, a greater understanding of the mechanisms along with evaluation of animal responses to diet changes allows diet adjustments to be made to optimize DMI as well as to optimize allocation of diet ingredients to animals. This paper discusses some of the characteristics of dietary ingredients that should be considered when formulating diets for lactating dairy cows and when allocating feeds to different groups of animals on the farm.

Animal Feed↗
PubMed1999

Inflammatory pseudotumors of the lung.

BACKGROUND: Inflammatory pseudotumors of the lung are rare and often present a dilemma for the surgeon at time of operation. We reviewed our experience with patients who have this unusual pathology. METHODS: Between February 1946 and September 1993, 56,400 general thoracic surgical procedures were performed at the Mayo Clinic. Twenty-three patients (0.04%) had resection of an inflammatory pseudotumor of the lung. There were 12 women and 11 men. Median age was 47 years (range, 5 to 77 years). Six patients (26%) were less than 18 years old. All pathologic specimens were re-reviewed, and the diagnosis of inflammatory pseudotumor was confirmed. Eighteen patients (78%) were symptomatic which included cough in 12, weight loss in 4, fever in 4, and fatigue in 4. Four patients had prior incomplete resections performed elsewhere and underwent re-resection because of growth of residual pseudotumor. Wedge excision was performed in 7 patients, lobectomy in 6, pneumonectomy in 6, chest wall resection in 2, segmentectomy in 1, and bilobectomy in 1. Complete resection was accomplished in 18 patients (78%). Median tumor size was 4.0 cm (range, 1 to 15 cm). There were no operative deaths. Follow-up was complete in all patients and ranged from 3 to 27 years (median, 9 years). RESULTS: Overall 5-year survival was 91%. Nineteen patients are currently alive. Cause of death in the remaining 4 patients was unrelated to pseudotumor. The pseudotumor recurred in 3 of the 5 patients who had incomplete resection; 2 have had subsequent complete excision with no evidence of recurrence 8 and 9 years later. CONCLUSIONS: We conclude that inflammatory pseudotumors of the lung are rare. They often occur in children, can grow to a large size, and are often locally invasive, requiring significant pulmonary resection. Complete resection, when possible, is safe and leads to excellent survival. Pseudotumors, which recur, should be re-resected.

Adolescent↗
PubMed1999

Early and long-term results of prosthetic chest wall reconstruction.

OBJECTIVE: The purpose of this report is to evaluate our results in patients who underwent prosthetic bony reconstruction after chest wall resection. METHODS: We retrospectively reviewed all patients who underwent chest wall resection and reconstruction with prosthetic material at the Mayo Clinic. RESULTS: From January 1, 1977, to December 31, 1992, 197 patients (109 male patients and 88 female patients) underwent chest wall resection and reconstruction with prosthetic material. Median age was 59 years (range, 11-86 years). The indication for resection was recurrent chest wall malignancy in 65 patients (33.0%), primary chest wall malignancy in 62 patients (31.5%), contiguous lung or breast carcinoma in 58 patients (29.4%), and other reasons in 12 patients (6.1%). Three patients (1.5%) each had an open draining wound. This review covers 2 time periods. Sixty-four patients (32.5%) underwent reconstruction with polypropylene mesh during the period from 1977 to 1986. One hundred thirty-three patients (67.5%) underwent reconstruction with polytetrafluoroethylene from 1984 to 1992. Soft tissue coverage was achieved with transposed muscle in 116 patients (58.9%), local tissue in 81 patients (41.1%), and omentum in 3 patients (1.5%). There were 8 deaths (operative mortality rate, 4.1%). Ninety-one patients (46.2%) experienced complications. Seromas occurred in 14 patients (7.1%). Wound infections occurred in 9 patients (4.6%; 5 patients with polypropylene mesh and 4 patients with polytetrafluoroethylene). The prosthesis was removed in all 5 patients with polypropylene mesh and in none of the patients with polytetrafluoroethylene. Follow-up was complete in 179 operative survivors (94.7%) and ranged from 1 to 204 months (median, 26 months). A well-healed asymptomatic wound was present in 127 patients (70.9%). CONCLUSIONS: Chest wall resection and reconstruction with prosthetic material will yield satisfactory results in most patients. Little difference exists between polypropylene mesh and polytetrafluoroethylene.

Adolescent↗
PubMed1999

Results of reoperation on the upper esophageal sphincter.

OBJECTIVE: Reoperation on the upper esophageal sphincter is infrequent. We reviewed our experience in patients who underwent reoperation on the upper esophageal sphincter. METHODS: This is a retrospective report of accumulative series from 2 separate institutions. RESULTS: From September 1, 1976, to February 28, 1997, 37 patients underwent reoperation on the upper esophageal sphincter for recurrent or persistent obstructive symptoms. There were 29 men and 8 women. The median age was 69 years (range, 38-87 years). The original indication for the operation was a pharyngoesophageal (Zenker's) diverticulum in 33 patients (89.2%), oculopharyngeal dystrophy in 3 patients (8.1%), and muscular dystrophy in 1 patient (2.7%). One prior upper esophageal sphincter operation had been performed in 26 patients (70.3%), two operations in 9 patients (24. 3%), and three operations in 2 patients (5.4%). All patients were symptomatic; 35 patients (94.6%) had dysphagia; 23 patients (62.2%) had regurgitation; and 12 patients (32.4%) had episodes of aspiration. Thirty of the patients (91.0%) with Zenker's diverticulum were found to have a recurrent or persistent diverticulum at reoperation. A diverticulectomy and cricopharyngeal myotomy were performed in 23 patients (62.2%); cricopharyngeal myotomy alone, in 7 patients (18.9%); diverticulopexy and cricopharyngeal myotomy, in 6 patients (16.2%); and diverticulectomy alone, in 1 patient (2.7%). There were no operative deaths. Complications developed in 10 patients (27.0%). Follow-up was complete in 34 patients (91.9%) and ranged from 2 to 149 months (median, 39 mo). Thirty-two patients (94.1%) were improved. Functional results were classified as excellent in 26 patients (76. 5%), good in 2 patients (5.9%), fair in 4 patients (11.7%), and poor in 2 patients (5.9%). CONCLUSIONS: Reoperation for patients who have persistent or recurrent symptoms after an operation on the upper esophageal sphincter is associated with acceptable morbidity and mortality rates. Resolution of symptoms occurs in most patients.

Adult↗
PubMed1999

Treatment of epiphrenic diverticula.

Epiphrenic diverticulum is a rare disorder of the lower esophagus, thought to be related to an esophageal motility disorder. Treatment should involve removal of diverticulum and myotomy. Although the surgery is technically a difficult one, the long-term outcome should be excellent.

Diverticulum, Esophageal↗
PubMed1999

Effects of brown midrib 3 mutation in corn silage on dry matter intake and productivity of high yielding dairy cows.

The effects of enhanced in vitro neutral detergent fiber (NDF) digestibility of corn silage on dry matter intake (DMI) and milk yield were evaluated using 32 Holstein cows in a crossover design with 28-d periods. At the beginning of the experiment, cows were 89 d in milk and yielded 45.6 kg/d of milk. Experimental diets contained either brown midrib (bm3) corn silage or isogenic normal corn silage (control) at 44.6% of DM. The NDF digestibility estimated by 30-h in vitro fermentation was higher for bm3 corn silage by 9.7 units. Contents of NDF and lignin were lower for bm3 corn silage by 1.8 and 0.8 units, respectively. Diets were formulated to contain 19% crude protein and 31% NDF and to have a forage to concentrate ratio of 56:44. Daily DMI, milk yield (3.5% fat-corrected milk), and solids-corrected milk were 2.1, 2.6, and 2.7 kg higher, respectively, for cows fed bm3 corn silage. The milk protein and lactose contents were greater for bm3 treatment, but milk fat content was not. Individual milk yield responses of the cows to bm3 treatment were positively related to pretrial milk yield, and DMI response tended to be positively related to pretrial milk yield. Enhanced in vitro NDF digestibility was associated with higher energy intake, which resulted in increased milk yield.

Animals↗
PubMed1999

Evaluation of the importance of the digestibility of neutral detergent fiber from forage: effects on dry matter intake and milk yield of dairy cows.

Effects of the digestibility of neutral detergent fiber (NDF) from forage on performance of dairy cows were evaluated statistically using treatment means for 13 sets of forage comparisons reported in the literature. All comparisons reported significant differences in NDF digestibilities of forages in situ or in vitro. Treatment means were blocked by study or by additional factorial treatment within a study to remove variation among experiments. The statistical model included random effect of block, fixed factorial effect of NDF digestibility (high or low), and dietary NDF concentration as a covariate. Enhanced NDF digestibility of forage significantly increased dry matter intake (DMI) and milk yield. A one-unit increase in NDF digestibility in vitro or in situ was associated with a 0.17-kg increase in DMI and a 0.25-kg increase in 4% fat-corrected milk. Differences in NDF digestibility between treatments were greater when measured in vitro or in situ than when measured in vivo. Digestibility of NDF in vitro or in situ might be a better indicator of DMI than NDF digestibility in vivo because forages with high in vitro or in situ NDF digestibilities might have shorter rumen retention times, allowing greater DMI at the expense of NDF digestibility in vivo. Digestibility of NDF is an important parameter of forage quality.

Animals↗
PubMed1999

Effect of energy and protein density of prepartum diets on fat and protein metabolism of dairy cattle in the periparturient period.

To determine if increased nutrient density in prepartum diets improves nutrient balance of peripartum cows, we blocked 40 Holstein cows and 40 heifers by expected date of parturition and assigned them randomly within blocks to one of four treatment diets varying in density of net energy for lactation (NEL) and crude protein (CP). Diets were 1.30 Mcal of NEL/kg and 12.2% CP, 1.49 Mcal of NEL/kg and 14.2% CP, 1.61 Mcal of NEL/kg and 15.9% CP, and 1.48 Mcal of NEL/kg and 16.2% CP. These diets were fed ad libitum from 25 d prepartum until parturition, and all cows were fed the same diet after calving. Increased nutrient-density of prepartum diets did not decrease feed intake. Compared to animals fed the lowest density, those fed the highest density consumed more NEL (20 vs. 14 Mcal/d) and gained more body condition, backfat, and body weight. They also had less nonesterified fatty acids in plasma (176 vs. 233 microM) and more insulin-like growth factor-I in plasma (472 vs. 390 ng/ml) during the last 2 wk prepartum and less triglyceride in liver at parturition (0.9 vs. 1.5%, wet tissue basis). Quadratic effects of energy density were not observed, and the addition of protein in the medium energy diet had no effect. Prepartum diets did not alter any variables during lactation. In conclusion, increasing the energy and protein density up to 1.6 Mcal of NEL/kg and 16% CP in diets during the last month before parturition improves nutrient balance of cattle prepartum and decreases hepatic lipid content at parturition.

Animal Nutritional Physiological Phenomena↗
PubMed1999

A dairy herd model for use in whole farm simulations.

A dairy herd submodel was created for integration with other farm submodels to form DAFOSYM, a dairy farm simulation model. The herd submodel determines the best mix of available feeds to meet the fiber, energy, and protein requirements for each of six animal groups. The groups are early-, mid-, late-, and nonlactating cows, heifers over 1 yr old, and younger heifers. Feed intake, milk production, and manure dry matter and nutrient (N, P, and K) excretions are functions of the nutrient content of the diets. Required feed characteristics include crude protein, rumen degradable protein, acid detergent insoluble protein, net energy of lactation, neutral detergent fiber, total digestible nutrients, P, and K concentrations. Feed intake is predicted with fill and roughage units. These units are functions of feed neutral detergent fiber adjusted for particle size distribution and the relative rate of ruminal digestibility or physical effectiveness of the fiber. The herd submodel predicted feed intakes, nutrient requirements, diets, and manure excretions similar to those recommended or measured for dairy animals. When integrated with other farm components in DAFOSYM, the comprehensive model provides a useful tool for evaluating the long-term performance and economics of alternative dairy farm systems.

Animal Feed↗
PubMed1999

Alpha1-antitrypsin deficiency allele carriers among lung cancer patients.

Lung cancer (LC) and chronic obstructive pulmonary lung diseases (COPDs; including emphysema and chronic bronchitis) share a common etiology. Despite the known associations of alpha1-antitrypsin deficiency (alpha1AD) with COPD and COPD with LC, few studies examined the association of alpha1AD alleles and LC. We hypothesize that heterozygous individuals who carry a deficient allele of the alpha1AD gene Pi (protease inhibitor locus) are at an increased risk of developing LC. The Pi locus is highly polymorphic with >70 variants reported. There are at least 10 alleles associated with deficiency in alpha1-antitrypsin. Using an exact binomial test, we compared the alpha1AD carrier rate in 260 newly diagnosed Mayo Clinic LC patients to the reported carrier rate in Caucasians in the United States (7%). alpha1AD carrier status, determined by isoelectric focusing assay, was examined with respect to the history of cigarette smoking, COPD, and histological types. Thirty-two of the 260 patients (12.3%; 95% confidence interval, 8.6-16.9%) carried an alpha1AD allele, which was significantly higher than expected (P = 0.002). Twenty-four of the 32 carriers had allele S, 6 had allele Z, and 2 had allele I. Patients who never smoked cigarettes were three times more likely to carry a deficient allele (20.6%; P = 0.008), although smokers had a higher carrier rate (11.1%; P = 0.025) when compared with the 7% rate. Patients with squamous cell or bronchoalveolar carcinoma had a significantly higher carrier rate than expected (15.9% and 23.8%, P < or = 0.01, respectively). Our preliminary findings suggest that individuals who carry an alpha1AD allele may have an increased risk for developing LC, specifically squamous cell or bronchoalveolar carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed1998

Zenker's diverticulum in the elderly: is operation justified?

BACKGROUND: Surgical correction of symptomatic Zenker's diverticulum is effective; however, elderly symptomatic patients may be denied surgical intervention because of perceived increased risks. METHODS: To address this concern, we reviewed 75 patients (46 men and 29 women) found to have this condition during the past two decades. RESULTS: Median age was 79 years (range, 75 to 91 years). Preoperative symptoms included dysphagia in 69 patients (92%), regurgitation in 61 (81%), pneumonia in 9 (12%), halitosis in 3 (4%), and weight loss in 1 (1%). Gastroesophageal reflux symptoms were noted in 27 patients (36%). Diagnosis was made by barium swallow in 63 patients, esophagoscopy in 5, and a combination of both in 7. Surgical procedures included both diverticulectomy and myotomy in 57 patients (76%), myotomy alone in 9 (12%), diverticulopexy and myotomy in 5 (7%), and diverticulectomy alone in 4 (5%). There was no in-hospital mortality. Complications occurred in 8 patients (11%) and included esophagocutaneous fistula in 4, pneumonia and urinary tract infection in 1, and wound infection, myocardial infarction, and persistent diverticulum in 1 each. Follow-up was available in 72 patients (96%) and ranged from 8 days to 17 years (median, 3.3 years). At follow-up, 64 patients (88%) were asymptomatic and 4 (6%) were improved with minimal symptoms. The remaining 4 patients (6%) have had varying degrees of dysphagia and all have been treated with periodic esophageal dilations. CONCLUSIONS: Operation for symptomatic Zenker's diverticulum in the elderly is safe and effective and will result in resolution of symptoms and improved quality of life in most patients.

Aged↗