Hereditary ovarian tumour syndromes: current update on genetics and imaging

Hereditary ovarian tumour syndromes are a diverse group of hereditary syndromes characterised by the development of specific histotypes of ovarian neoplasms. While BRCA syndromes are exclusively associated with high-grade serous carcinomas, patients with Lynch syndrome show a preponderance of endometrioid subtype of ovarian and endometrial carcinomas. Distinct non-epithelial phenotypes, such as sex cord stromal tumours with annular tubules, Sertoli-Leydig cell tumours, and small cell carcinoma of the hypercalcaemic type occur in patients with Peutz-Jeghers, DICER1, and rhabdoid tumour predisposition syndromes, respectively. Gorlin-Goltz syndrome is characterised by the development of bilateral, multiple ovarian fibromas in 14-24% of patients. Ovarian steroid cell tumours and broad ligament papillary cystadenomas are characteristically found in women with von Hippel-Lindau syndrome. Recent studies have allowed the characterisation of tumour genetics and associated oncological pathways that contribute to tumourigenesis. Implications of the diagnosis of these syndromes on screening, management, and prognosis are discussed.

A Comparative Evaluation of Intracanal Calcium Hydroxide Removal with Hand File, Rotary File, and Passive Ultrasonic Irrigation: An In Vitro Study

Aim

The aim of this study was to compare the effectiveness of hand file (K-file), rotary file (HERO shaper), and passive ultrasonic irrigation (PUI; U-file) in removing Ca(OH)₂ from the root canal.

Materials and Methods

Thirty single-rooted teeth were collected and decoronated to standardize the length to 14 mm. Cleaning and shaping were conducted using HERO shaper rotary files (up to no. 25, 4% taper). Ca(OH)₂ powder was mixed with normal saline and filled into the canals using lentulo spiral and the orifice was sealed with zinc oxide eugenol. After 7 days of incubation, samples were divided into three groups of 10 samples each: Group I (hand files)-no. 20 K-file; Group II (rotary files)-no. 25, 4% HERO shaper; Group III (PUI)-no. 20 U-file. Ca(OH)₂ paste was removed using 2 mL of 3% sodium hypochlorite solution followed by 1-minute activation of the respective file system. All the samples were finally irrigated with 17% ethylenediaminetetraacetic acid and flushed with distilled water.

Results

Ultrasonic group was more effective in removing Ca(OH)₂ followed by HERO shaper and hand file.

Conclusion

It was concluded that PUI had the highest ability to remove Ca(OH)₂ from the root canal walls.

Musculoskeletal Disorders and Mental Health-related Issues as Occupational Hazards among Dental Practitioners in Salem City: A Cross-sectional Study

Background:

Like in any other profession, dental surgeons are also afflicted by many occupational health hazards such as Musculoskeletal disorders (MSD) and mental health related issues.

Aims:

To assess the distribution of MSD and mental health related issues amidst dentists in Salem City according to age, sex and number of working hours per week.

Objectives:

A survey was organized to check the rate of occurrence of these occupational health hazards among dental practitioners in Salem city.

Materials and Methods:

The study was conducted among one hundred and fifty dentists practicing in Salem City in the form of questionnaire. Dentists were asked about any occupational disease that they suffered related to a musculo–skeletal pain and its location whether in the back, upper limbs or lower limbs. In addition to this, dentists were asked about mental stress that they had experienced.

Results:

MSD showed higher rate of prevalence compared to mental health related issues.

Conclusion:

The application of preventive measures is necessary, in view of the high rate of these disorders in the society of dental practitioners.

A comparative evaluation of microleakage of restorations using silorane-based dental composite and methacrylate-based dental composites in Class II cavities: An in vitro study

Aim:

The aim of this in vitro study was to evaluate and compare the microleakage of restorations using low shrinkage silorane-based dental composite and methacrylate-based dental composites in Class II cavity at the occlusal and gingival margins.

Materials and Methods:

Sixty mandibular molars were collected and divided into three experimental groups and one negative control group. Class II slot cavity was prepared on the mesial surface. Experimental groups were restored with Group I: silorane-based microhybrid composite, Group II: methacrylate-based nanohybrid composite, and Group III: Methacrylate-based microhybrid composite, respectively. Group IV: negative control. The samples were thermocycled, root apices were sealed with sticky wax and coated with nail varnish except 1 mm around the restoration. This was followed by immersion in 2% Rhodamine-B dye solution under vacuum at room temperature for 24 h. Then, the samples were sectioned longitudinally in the mesiodistal direction and evaluated under stereomicroscope ×40 magnification. Scoring was done according to the depth of dye penetration in to the cavity. Statistical analysis of the data was done.

Results:

The results were that no statistically significant difference in the microleakage at the occlusal margin for all the restorative materials, whereas at the gingival margin, silorane-based microhybrid composite showed less microleakage than the methacrylate-based nano- and micro-hybrid composites.

Conclusion:

In general, silorane-based microhybrid composite had less microleakage among the other materials used in this in vitro study.

Reliability, validity, and responsiveness of the Western Ontario and McMaster Universities Osteoarthritis Index for elderly patients with a femoral neck fracture

BACKGROUND

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) has been extensively evaluated in groups of patients with osteoarthritis, yet not in patients with a femoral neck fracture. This study aimed to determine the reliability, construct validity, and responsiveness of the WOMAC compared with the Short Form-12 (SF-12) and the EuroQol 5D (EQ-5D) questionnaires for the assessment of elderly patients with a femoral neck fracture.

METHODS

Reliability was tested by assessing the Cronbach alpha. Construct validity was determined with the Pearson correlation coefficient. Change scores were calculated from ten weeks to twelve months of follow-up. Standardized response means and floor and ceiling effects were determined. Analyses were performed to compare the results for patients less than eighty years old with those for patients eighty years of age or older.

RESULTS

The mean WOMAC total score was 89 points before the fracture in the younger patients and increased from 70 points at ten weeks to 81 points at two years postoperatively. In the older age group, these scores were 86, 75, and 78 points. The mean WOMAC pain scores before the fracture and at ten weeks and two years postoperatively were 92, 76, and 87 points, respectively, in the younger age group and 92, 84, and 93 points in the older age group. Function scores were 89, 68, and 79 points for the younger age group and 84, 71, and 73 points for the older age group. The Cronbach alpha for pain, stiffness, function, and the total scale ranged from 0.83 to 0.98 for the younger age group and from 0.79 to 0.97 for the older age group. Construct validity was good, with 82% and 79% of predefined hypotheses confirmed in the younger and older age groups, respectively. Responsiveness was moderate. No floor effects were found. Moderate to large ceiling effects were found for pain and stiffness scales at ten weeks and twelve months in younger patients (18% to 36%) and in the older age group (38% to 53%).

CONCLUSIONS

The WOMAC showed good reliability, construct validity, and responsiveness in both age groups of elderly patients with a femoral neck fracture who had been physically and mentally fit before the fracture. The instrument is suitable for use in future clinical studies in these populations.

CLINICAL RELEVANCE

The results are based on two clinical trials. The questionnaires used concern pure, clinically relevant issues (ability to walk, climb stairs, etc.). Moreover, the results can be used for future research comparing clinical outcomes (or treatments) for populations with a femoral neck fracture.

Role of dietary zinc in heat-stressed poultry: a review

High ambient temperatures compromise performance and productivity through reducing feed intake and decreasing nutrient utilization, growth rate, egg production, egg quality, and feed efficiency, which lead to economic losses in poultry. Environmental stress also leads to oxidative stress associated with a reduced antioxidant status in the bird in vivo, as reflected by increased oxidative damage and lowered plasma concentrations of antioxidant vitamins (e.g., vitamins E, A, and C) and minerals (e.g., Zn). Zinc has an important role in numerous biological processes in avian and mammalian species. For instance, Zn is an essential component of many enzymes, and it has both structural and catalytic functions in metalloenzymes. Furthermore, dietary Zn is required for normal immune function as well as proper skeletal development and maintenance. One of the most important functions of Zn is related to its antioxidant role and its participation in the antioxidant defense system. This work compiles past and present information about the role of Zn in heat-stressed poultry health.

A stability-indicating HPLC assay method for docetaxel

A novel stability-indicating high-performance liquid chromatographic assay method was developed and validated for docetaxel in the presence of degradation products generated from forced decomposition studies. A gradient HPLC method was developed to separate the drug from the degradation products, using a Hichrom RPB HPLC column. Mixture of water and acetonitrile was used as mobile phase. The flow rate was 1.0 ml/min and the detection was done at 230 nm. Using the above method one can carry out the quantitative estimation of impurity namely DCT-1 and docetaxel. The developed gradient LC method was subsequently validated.

Zinc activates NF-kappaB in HUT-78 cells

Zinc is essential for human health, and its deficiency in human beings results in growth failure, immune disorders affecting Th1 functions, decreased interleukin-2 (IL-2) production, and cognitive impairment. Nearly 2000 transcription factors require zinc for their structural integrity; however, it is not known whether cellular zinc deficiency results in any change in activation of any of the transcription factors. Inasmuch as NF-kappaB binds to the promoter enhancer area of IL-2 and IL-2Ralpha genes, we investigated the effect of zinc deficiency on activation of NF-kappaB and its binding to DNA in HUT-78, a Th0 malignant human lymphoblastoid cell line. We show here for the first time that in zinc-deficient HUT-78 cells, phosphorylated IkappaB, and IKK, ubiquitinated IkappaB and binding of NF-kappaB to DNA were all significantly decreased. Zinc increased the translocation of NF-kappaB from cytosol to nucleus. We also demonstrate that the binding of recombinant NF-kappaB (p50)(2) to DNA in HUT-78 cells was zinc specific. We conclude that zinc plays an important role in the activation of NF-kappaB in HUT-78 cells.

Effects of zinc deficiency on Th1 and Th2 cytokine shifts

Nutritional deficiency of zinc is widespread throughout developing countries, and zinc-deficient persons have increased susceptibility to a variety of pathogens. Zinc deficiency in an experimental human model caused an imbalance between Th1 and Th2 functions. Production of interferon-gamma and interleukin (IL)-2 (products of Th1) were decreased, whereas production of IL-4, IL-6, and IL-10 (products of Th2) were not affected during zinc deficiency. Zinc deficiency decreased natural killer cell lytic activity and percentage of precursors of cytolytic T cells. In HuT-78, a Th0 cell line, zinc deficiency decreased gene expression of thymidine kinase, delayed cell cycle, and decreased cell growth. Gene expression of IL-2 and IL-2 receptors (both alpha and beta) and binding of NF-kappaB to DNA were decreased by zinc deficiency in HuT-78. Decreased production of IL-2 in zinc deficiency may be due to decreased activation of NF-kappaB and subsequent decreased gene expression of IL-2 and IL-2 receptors.

Duration of symptoms and plasma cytokine levels in patients with the common cold treated with zinc acetate. A randomized, double-blind, placebo-controlled trial

BACKGROUND

Adults and children in the United States get two to six colds per year. Evidence that zinc is effective therapy for colds is inconsistent.

OBJECTIVE

To test the efficacy of zinc acetate lozenges in reducing the duration of symptoms of the common cold.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Detroit Medical Center, Detroit, Michigan.

PATIENTS

50 ambulatory volunteers recruited within 24 hours of developing symptoms of the common cold.

INTERVENTION

Participants took one lozenge containing 12.8 mg of zinc acetate or placebo every 2 to 3 hours while awake as long as they had cold symptoms.

MEASUREMENTS

Subjective symptom scores for sore throat, nasal discharge, nasal congestion, sneezing, cough, scratchy throat, hoarseness, muscle ache, fever, and headache were recorded daily for 12 days. Plasma zinc and proinflammatory cytokine levels were measured on day 1 and after participants were well.

RESULTS

Forty-eight participants completed the study (25 in the zinc group and 23 in the placebo group). Compared with the placebo group, the zinc group had shorter mean overall duration of cold symptoms (4.5 vs. 8.1 days), cough (3.1 [95% CI, 2.1 to 4.1] vs. 6.3 [CI, 4.9 to 7.7] days), and nasal discharge (4.1 [CI, 3.3 to 4.9] vs. 5.8 [CI, 4.3 to 7.3] days) and decreased total severity scores for all symptoms (P < 0.002, test for treatment x time interaction). Mean changes in soluble interleukin-1 receptor antagonist level differed nonsignificantly between the zinc group and the placebo group (difference between changes, -89.4 pg/mL [CI, -243.6 to -64.8 pg/mL]).

CONCLUSION

Administration of zinc lozenges was associated with reduced duration and severity of cold symptoms, especially cough. Improvement in clinical symptoms with zinc treatment may be related to a decrease in proinflammatory cytokine levels; however, in this study, the observed differences between changes in cytokine levels in zinc and placebo recipients were not significant.

Effect of zinc supplementation on incidence of infections and hospital admissions in sickle cell disease (SCD)

Zinc deficiency is a common nutritional problem in adult sickle-cell disease (SCD) patients. Hyperzincuria and increased requirement of zinc due to continued hemolysis in SCD are probable bases for zinc deficiency in these patients. Zinc deficiency affects adversely T-helper1 (TH1) functions and cell mediated immunity and interleukin (IL)-2 production is decreased in zinc deficient subjects. We hypothesized that zinc supplementation will improve T-helper1 function and decrease incidence of infections in patients with SCD. We tested this hypothesis in 32 SCD subjects who were divided in three groups (Grs A, B, and C). Grs A (n = 11) and B (n = 10) were zinc deficient based on cellular zinc criteria and Gr C (n = 11) were zinc sufficient. Gr A subjects were observed for 1 year (baseline), following which they received zinc acetate (50 to 75 mg of elemental zinc orally daily) for 3 years. Gr B subjects were observed for 1 year (baseline), following which they received placebo for 1 year and then switched to zinc supplementation (50 to 75 mg of elemental zinc orally daily) for 2 years. Gr C subjects did not receive any intervention inasmuch as they were zinc sufficient. Prolonged zinc supplementation resulted in an increase in lymphocyte and granulocyte zinc (P = 0.0001), and an increase in interleukin-2 production (P = 0.0001), decreased incidence of documented bacteriologically positive infections (P = 0.0026), decreased number of hospitalizations and decreased number of vaso-occlusive pain crisis (P = 0.0001). The predominant pathogens isolated were staphylococci and streptococci involving the respiratory tract and aerobic gram-negative bacteria, particularly Escherichia coli, involving the urinary tract. Further confirmation of our observations will require prospective studies of zinc supplementation in a larger number of SCD patients.

Zinc and immunity

Nutritional deficiency of zinc is widespread throughout the developing countries and a conditioned deficiency of zinc is known to occur in many diseased states. Zinc is known to play an important role in the immune system and zinc deficient subjects may experience increased susceptibility to a variety of pathogens. We have studied the effects of a mild deficiency of zinc on T cells in an experimental model of human zinc deficiency. We showed that T cell functions were affected adversely even when the deficiency of zinc was mild in humans. Characteristically during zinc deficiency, the serum thymulin activity (a thymic hormone) was decreased which was restored following zinc supplementation. Our studies also showed that zinc deficiency caused an imbalance between TH1 and TH2 functions. The production of IFN-g, IL-2, TNF-a (products of TH1 cells) were decreased, whereas the production of IL-4, IL-6 and IL-10 (products of TH2) were not affected during zinc deficiency. T cell subpopulation studies revealed that the CD4+ CD45RA+ to CD4+ CD45RO+ ratio was decreased as a result of zinc deficiency, suggesting that zinc may be required for the regeneration of new CD4+ T cells. We further documented that zinc deficiency decreased NK cell lytic activity and caused a decrease in the percentage of CD8+ CD73+ T cells which are known to be predominantly precursors of cytotoxic T cells. In a suitable cell culture model our studies revealed that the gene expression of a DNA synthesizing enzyme TK was affected adversely which resulted in delayed cell cycle and decreased cell growth. The above immunological consequences of zinc deficiency may be responsible for decreased cell mediated immune functions in zinc deficient subjects.

Zinc and immunity

Nutritional deficiency of zinc is widespread throughout the developing countries and a conditioned deficiency of zinc is known to occur in many diseased states. Zinc is known to play an important role in the immune system and zinc deficient subjects may experience increased susceptibility to a variety of pathogens. We have studied the effects of a mild deficiency of zinc on T cells in an experimental model of human zinc deficiency. We showed that T cell functions were affected adversely even when the deficiency of zinc was mild in humans. Characteristically during zinc deficiency, the serum thymulin activity (a thymic hormone) was decreased which was restored following zinc supplementation. Our studies also showed that zinc deficiency caused an imbalance between TH1 and TH2 functions. The production of IFN-g, IL-2, TNF-a (products of TH1 cells) were decreased, whereas the production of IL-4, IL-6 and IL-10 (products of TH2) were not affected during zinc deficiency. T cell subpopulation studies revealed that the CD4+ CD45RA+ to CD4+ CD45RO+ ratio was decreased as a result of zinc deficiency, suggesting that zinc may be required for the regeneration of new CD4+ T cells. We further documented that zinc deficiency decreased NK cell lytic activity and caused a decrease in the percentage of CD8+ CD73+ T cells which are known to be predominantly precursors of cytotoxic T cells. In a suitable cell culture model our studies revealed that the gene expression of a DNA synthesizing enzyme TK was affected adversely which resulted in delayed cell cycle and decreased cell growth. The above immunological consequences of zinc deficiency may be responsible for decreased cell mediated immune functions in zinc deficient subjects.

Nutritional and zinc status of head and neck cancer patients: an interpretive review

In this review, we provide evidence based on our studies, for zinc deficiency and cell mediated immune disorders, and the effects of protein and zinc status on clinical morbidities in patients with head and neck cancer. We investigated subjects with newly diagnosed squamous cell carcinoma of the oral cavity, oropharynx, larynx, and hypopharynx. Patients with metastatic disease and with severe co-morbidity were excluded. Nutritional assessment included dietary history, body composition, and prognostic nutritional index (PNI) determination. Zinc status was determined by zinc assay in plasma, lymphocytes, and granulocytes. Pretreatment zinc status and nutritional status were correlated with clinical outcomes in 47 patients. Assessment of immune functions included production of TH1 and TH2 cytokines, T cell subpopulations and cutaneous delayed hypersensitivity reaction to common antigens. At baseline approximately 50% of our subjects were zinc-deficient based on cellular zinc criteria and had decreased production of TH1 cytokines but not TH2 cytokines, decreased NK cell lytic activity and decreased proportion of CD4+ CD45RA+ cells in the peripheral blood. The tumor size and overall stage of the disease correlated with baseline zinc status but not with PNI, alcohol intake, or smoking. Zinc deficiency was associated with increased unplanned hospitalizations. The disease-free interval was highest for the group which had both zinc sufficient and nutrition sufficient status. Zinc deficiency and cell mediated immune dysfunctions were frequently present in patients with head and neck cancer when seen initially. Zinc deficiency resulted in an imbalance of TH1 and TH2 functions. Zinc deficiency was associated with increased tumor size, overall stage of the cancer and increased unplanned hospitalizations. These observations have broad implications in the management of patients with head and neck cancer.

Myxoma of maxilla

A rare case of Myxoma of right maxilla in a 25 year female, presenting as-bilateral nasal obstruction with destruction of the septum and maxillary antral bone is reported.

Zinc and immune function: the biological basis of altered resistance to infection

Zinc is known to play a central role in the immune system, and zinc-deficient persons experience increased susceptibility to a variety of pathogens. The immunologic mechanisms whereby zinc modulates increased susceptibility to infection have been studied for several decades. It is clear that zinc affects multiple aspects of the immune system, from the barrier of the skin to gene regulation within lymphocytes. Zinc is crucial for normal development and function of cells mediating nonspecific immunity such as neutrophils and natural killer cells. Zinc deficiency also affects development of acquired immunity by preventing both the outgrowth and certain functions of T lymphocytes such as activation, Th1 cytokine production, and B lymphocyte help. Likewise, B lymphocyte development and antibody production, particularly immunoglobulin G, is compromised. The macrophage, a pivotal cell in many immunologic functions, is adversely affected by zinc deficiency, which can dysregulate intracellular killing, cytokine production, and phagocytosis. The effects of zinc on these key immunologic mediators is rooted in the myriad roles for zinc in basic cellular functions such as DNA replication, RNA transcription, cell division, and cell activation. Apoptosis is potentiated by zinc deficiency. Zinc also functions as an antioxidant and can stabilize membranes. This review explores these aspects of zinc biology of the immune system and attempts to provide a biological basis for the altered host resistance to infections observed during zinc deficiency and supplementation.

Zinc may regulate serum leptin concentrations in humans

OBJECTIVE

Leptin, the product of the ob gene, plays a key role in a feedback loop that maintains energy balance by signaling the state of energy stores to the brain and by influencing the regulation of appetite and energy metabolism. Zinc also plays an important role in appetite regulation. Thus, we evaluated the relationship between zinc status and the leptin system in humans.

METHODS

We studied nine healthy men with marginal zinc deficiency, induced by dietary means, before and after zinc supplementation.

RESULTS

Zinc restriction decreased leptin levels while zinc supplementation of zinc-depleted subjects increased circulating leptin levels. In addition, zinc supplementation increased IL-2 and TNF-alpha production that could be responsible for the observed increase in leptin concentrations.

CONCLUSIONS

Zinc may influence serum leptin levels, possibly by increasing the production of IL-2 and TNF-alpha.

Effects of zinc and nutritional status on clinical outcomes in head and neck cancer

The head and neck cancer patient often presents with both protein malnutrition and trace element deficiencies. Zinc has been found to be deficient in many head and neck cancer patients. In this study, pretreatment zinc status and nutritional status (measured by the Prognostic Nutritional Index [PNI]) were correlated with clinical outcomes in 47 patients. The patients were followed-up for a median of 52 mo from the time of enrollment. Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no such correlation was seen with PNI, alcohol intake, or smoking in our subjects. The results also showed that impaired zinc status was associated with an increased number of treatment morbidities, unplanned hospitalizations, and treatment delays (P < 0.05). Nutritional status was not associated with any studied outcome variable. The disease-free interval was highest for the group which had both zinc-sufficient and nutrition-sufficient status. Although our data do not prove conclusively, they do suggest that impaired zinc status at presentation may contribute to treatment morbidity, and that for an optimal mean disease-free interval, a sufficient zinc and nutritional status is required.

Cardiovascular responses to application of lower body negative pressure of male volunteers in seated position

Lower body negative pressure (LBNP) has been used to evaluate orthostatic tolerance and for studying the effects of +Gz induced physiological strain and hence has great practical significance in aerospace medicine. Cardiovascular responses in man on application to LBNP (-40 mmHg) in seated (upright) position in a specially designed LBNP chamber have been studied in eight normal healthy male volunteers between the age group of 25-36 yrs. They were subjected to -40 mmHg negative pressure in steps of -10 mmHg for a duration of 5 min each. The total duration of the experiment was 20 min. Heart rate (HR), blood pressure (BP) Cardiac output (CO) were measured and mean blood pressure (MBP) and total peripheral resistance (TPR) were computed. The results indicate a significant increase in HR (P < 0.01), SV (P < 0.01). Studies on limited number of subjects on application to LBNP (40 mmHg) in supine position have also been carried out and compared with the physiological strain induced in subjects in seated position. Study of HR, SV, CO, responses of the subjects on exposure to LBNP in seated position elicit similar response in subjects exposed to +Gz stress as reported by other workers. It is concluded that LBNP technique can be used to study the effects of +Gz induced physiological strain in man.

Zinc deficiency in head and neck cancer patients

BACKGROUND

Although a great deal of attention has been given to protein and calorie malnutrition in patients with head and neck cancer, zinc status has not been assessed properly in such patients in the past.

METHODS

In this study we characterized zinc status by cellular zinc criteria and assessed several measures of protein and calorie malnutrition in patients with head and neck cancer. We determined prognostic nutritional index (PNI) based on serum albumin, serum transferrin, triceps skin fold measures, and delayed hypersensitivity, as proposed by Buzby et al. In this study, the baseline zinc status and PNI of 60 head and neck cancer patients were correlated with the tumor size and overall stage of the disease.

RESULTS

Our results showed that the tumor size and overall stage correlated significantly to zinc status whereas no correlation was seen with PNI, alcohol intake, or smoking in our study subjects.

CONCLUSION

We conclude that zinc status is a better indicator of tumor burden and stage of the disease in head and neck cancer patients than the patients' overall nutritional status.

Decreased expression of CD73 (ecto-5'-nucleotidase) in the CD8+ subset is associated with zinc deficiency in human patients

We used flow cytometry to observe the changes in T cell populations resulting from zinc deficiency in subjects with sickle cell anemia (SCA) and in healthy human volunteers without SCA. Zinc deficiency was associated with significant decreases in cellular zinc concentration, CD4+/CD8+ ratio, and percentage of CD73+ cells in the CD8+ population. The decrease in the percentage of CD73+ cells in the CD8+ subset was significantly correlated with lymphocyte zinc concentration and was accompanied by essentially no change in the percentage of CD11b+ cells in the CD8+ subset. Daily oral zinc supplementation in nine zinc-deficient human volunteers (25 mg elemental zinc) and in seven zinc-deficient SCA subjects (50 mg elemental zinc) resulted in increases in the absolute lymphocyte count and significant increases in the CD4+/CD8+ ratio and in the percentage of CD73+ cells in the CD8+ subset. In zinc-supplemented subjects, the increase in the percentage of CD73+ cells was accompanied by a significant decrease in the percentage of CD11b+ cells in the CD8+ subset. Changes in the CD4+/CD8+ and CD73+/CD11b- cell ratios in the CD8+ subset after treatment may provide a useful diagnostic criterion for zinc deficiency in humans.

Changes in cytokine production and T cell subpopulations in experimentally induced zinc-deficient humans

We have utilized an experimental model of human zinc deficiency for study of cytokines production by TH1 and TH2 cells. Additionally, we determined ratios of CD4+ to CD8+ and CD4+ CD45RA+ to CD4+CD45RO+ cells and percentages of CD73+ T cytolytic cells in the CD8+ subset. The data were collected during baseline, at the end of the zinc-restricted period, and following zinc repletion. Our results showed that functions of TH1 cells, as evidenced by production of interferon-gamma, interleukin-2 (IL-2), and tumor necrosis factor-alpha, were decreased, whereas functions of TH2 cells (production of IL-4, IL-6, and IL-10) were unaffected by zinc deficiency. Thus an imbalance between TH1 and TH2 cells resulted because of zinc deficiency in humans. Our studies also showed that zinc may be required for regeneration of new CD4+ T lymphocytes and maintenance of T cytolytic cells. We conclude that an imbalance between TH1 and TH2 cells, decreased recruitment of T naive cells, and decreased percentage of T cytolytic cells may account for decreased cell-mediated immune functions in zinc-deficient subjects.

Trace elements in head and neck cancer patients: zinc status and immunologic functions

In this study we have assessed zinc status and zinc-dependent cell-mediated immune functions (interleukin-2 production by mononuclear cells, natural killer cell lytic activity, and interleukin-1 beta production by mononuclear cells) in adult patients with squamous cell carcinoma of the upper aerodigestive tract at diagnosis and before any therapy was instituted. Inasmuch as significant interactions between zinc, copper, and iron exist, we also assayed the plasma copper level, serum iron level, and total iron-binding capacity in our patients. We recruited 30 cancer subjects and 21 control subjects. On the basis of cellular zinc criteria, we diagnosed a mild deficiency of zinc in 53% of cancer subjects. The plasma zinc level was not decreased in our subjects. A univariate analysis was applied by use of one-way analysis of variance comparing study variables among the three study groups (controls and zinc-deficient and zinc-sufficient cancer patients) and Tukey's multiple comparison test, and we showed that interleukin-2 production and natural killer lytic activity were decreased in zinc-deficient cancer patients. Interleukin-1 beta production (ELISA assay) was increased in both zinc-deficient and zinc-sufficient groups. Plasma copper level was not different, but the iron utilization was decreased in both groups of cancer subjects. We conclude that zinc deficiency and zinc-dependent immunologic dysfunctions are present in more than half of the patients with head and neck cancer in the Detroit area.

Analysis of 24-hour ECG in patients with panic disorder

Previous evidence suggests an increased cardiovascular morbidity in patients with panic disorder. In this study, we compared 24-hour ECG in patients with panic disorder (n = 22; age: 36.1 +/- 7.6 years) and healthy controls (n = 21; age: 34.6 +/- 10.0 years). The QTc intervals during the day or night were not significantly different between patients and controls. Ventricular ectopic beats were also not significantly different between the two groups. These results do not suggest any overt cardiac arrhythmias in this age group of patients with panic disorder.

Zinc deficiency: changes in cytokine production and T-cell subpopulations in patients with head and neck cancer and in noncancer subjects

Cell-mediated immune dysfunctions and susceptibility to infections have been observed in zinc-deficient human subjects. In this study, we investigated the production of cytokines and characterized the T-cell subpopulations in three groups of mildly zinc-deficient subjects. These included head and neck cancer patients, healthy volunteers who were found to have a dietary deficiency of zinc, and healthy volunteers in whom we induced zinc deficiency experimentally by dietary means. We used cellular zinc criteria for the diagnosis of zinc deficiency. We assayed enzyme-linked immunosorbent assay the production of cytokines from phytohemagglutinin-stimulated peripheral blood mononuclear cells and assessed by flow cytometry the differences in T-cell subpopulations. Our studies showed that the cytokines produced by TH1 cells were particularly sensitive to zinc status, inasmuch as the production of interleukin-2 (IL-2) and interferon-gamma were decreased even though the deficiency of zinc was mild in our subjects. TH2 cytokines (IL-4, IL-5, and IL-6) were not affected by zinc deficiency. Natural killer cell lytic activity also was decreased in zinc-deficient subjects. Recruitment of naive T cells (CD4+CD45 RA+) and CD8+ CD73+ CD11b-, precursors of cytolytic T cells, were decreased in mildly zinc-deficient subjects. An imbalance between the functions of TH1 and TH2 cells and changes in T-cell subpopulations are most probably responsible for cell-mediated immune dysfunctions in zinc deficiency.

Zinc deficiency affects cell cycle and deoxythymidine kinase gene expression in HUT-78 cells

Although zinc is known to be involved in cell proliferation and DNA synthesis, the mechanism by which zinc may regulate these processes is not understood. We have studied the role of zinc on cell proliferation and gene expression of a DNA synthesizing enzyme, deoxythymidine kinase (TK), in a T helper human malignant lymphoblastoid cell line (HUT-78). In zinc-deficient and zinc-sufficient media, the cell doubling time (mean +/- SD) of HUT-78 was 59 +/- 8 hours and 32.6 +/- 6 hours, respectively. The effect of zinc was T cell specific, inasmuch as the cell growth of another T malignant lymphoblastoid cell line, MOLT-3 (immature T cells), was not affected by zinc deficiency. Iron, copper, or manganese did not completely correct the cell growth of zinc-deficient HUT-78 cells. TK activity and the relative accumulation of TK-mRNA were significantly decreased in zinc-deficient cells during the G1 phase of cell cycle in comparison with zinc-sufficient cells. Nuclear run-on experiments and actinomycin-D studies showed that the transcription of TK-mRNA was affected adversely by zinc deficiency. Cell cycle studies showed that more zinc-deficient cells remained in S phase and did not undergo mitosis in comparison with zinc-sufficient cells. In conclusion, our data show that zinc is a T cell-specific growth factor and that a decreased gene expression of DNA-synthesizing enzyme TK in zinc-deficient HUT-78 cells in G1 phase affected adversely the DNA synthesis in S phase and delayed cell cycle.

Zinc status and serum testosterone levels of healthy adults

Zinc deficiency is prevalent throughout the world, including the USA. Severe and moderate deficiency of zinc is associated with hypogonadism in men. However, the effect of marginal zinc deficiency on serum testosterone concentration is not known. We studied the relationship between cellular zinc concentrations and serum testosterone cross-sectionally in 40 normal men, 20 to 80 y of age. In four normal young men (27.5 +/- 0.5 y), we measured serum testosterone before and during marginal zinc deficiency induced by restricting dietary zinc intake. We also measured serum testosterone in nine elderly men (64 +/- 9 y) who were marginally zinc deficient before and after 3 to 6 mo of supplementation with 459 mumol/ d oral zinc administered as zinc gluconate. Serum testosterone concentrations were significantly correlated with cellular zinc concentrations in the cross-sectional study (lymphocyte zinc versus serum testosterone, r = 0.43, p = 0.006; granulocyte zinc versus serum testosterone, r = 0.30, p = 0.03). Dietary zinc restriction in normal young men was associated with a significant decrease in serum testosterone concentrations after 20 weeks of zinc restriction (baseline versus post-zinc restriction mean +/- SD, 39.9 +/- 7.1 versus 10.6 +/- 3.6 nmol/L, respectively; p = 0.005). Zinc supplementation of marginally zinc-deficient normal elderly men for six months resulted in an increase in serum testosterone from 8.3 +/- 6.3 to 16.0 +/- 4.4 nmol/L (p = 0.02). We conclude that zinc may play an important role in modulating serum testosterone levels in normal men.

Zinc deficiency in women, infants and children

Zinc deficiency in humans is widespread and is more prevalent in areas where the population subsists on cereal proteins. Conditioned deficiency of zinc is seen in many diseased states. A mild deficiency of zinc in pregnancy is associated with increased maternal morbidity, abnormal taste sensation, prolonged gestation, inefficient labor, atonic bleeding, and increased risks to the fetus. Among the urban poor in the US, a marginal zinc intake during pregnancy was associated with increased risk of preterm and very preterm delivery. Factors responsible for zinc deficiency in premature infants include high fecal losses of zinc, low body stores of zinc at birth, and increased zinc requirement during rapid growth. Zinc supplemented infants demonstrated improved linear growth velocity and maximum motor development scores. Marginal and moderate growth impairment in children as a consequence of inadequate zinc intake has been reported from many developed and developing countries. In one study from Japan, 21 prepubertal children were diagnosed to have zinc deficiency. The caloric intake, growth velocity, serum zinc, and plasma insulin-like growth factor-1 increased significantly in the zinc supplemented group. The clinical manifestations of zinc deficiency include growth retardation, hypogonadism in males, neurosensory disorders, cell-mediated immunological dysfunctions, and skin changes. Approximately 300 enzymes are known to require zinc for their activities. Zinc is required for DNA synthesis, cell division and protein synthesis. Several hundreds of zinc containing nucleoproteins are probably involved in gene expression of various proteins. A deficiency of zinc also affects proliferation and maturity of lymphocytes adversely.

Zinc: an overview

Zn deficiency in humans is widespread throughout the world. It is more prevalent in areas where the population subsists on cereal proteins. Conditioned Zn deficiency is seen in many disease states. Its deficiency during growth periods results in growth failure and lack of gonadal development in males. Other effects of Zn deficiency include skin changes, poor appetite, mental lethargy, delayed wound healing, neurosensory disorders, and cell-mediated immune disorders. Severe Zn deficiency, as seen in acrodermatitis enteropathica (a genetic disorder), is fatal if Zn is not administered to these patients. A clinical diagnosis of marginal Zn deficiency in humans remains problematic. Assays of Zn in granulocytes and lymphocytes provide better diagnostic criteria for marginal Zn deficiency than plasma Zn. Approximately 300 enzymes are known to require Zn for their activities. Zn is required for DNA synthesis, cell division, and protein synthesis. Recently, we learned that Zn-finger proteins are involved in genetic expression of various growth factors and steroid receptors. We suspect that several hundred Zn-containing nucleoproteins are probably involved in gene expression of various proteins. Zn deficiency adversely affects lymphocyte proliferation. This may be related to the enzymatic role of Zn in DNA synthesis and cell division. Thymulin, a thymic hormone involved in T-lymphocyte maturation, is known to be Zn dependent and is adversely affected by Zn deficiency. Thus, an adverse effect of Zn deficiency may also be in lymphocyte differentiation and maturity. Zn deficiency is known to decrease interleukin 2 production by helper T lymphocytes, and abnormalities in T-lymphocyte subpopulations have been observed in Zn-deficient humans.(ABSTRACT TRUNCATED AT 250 WORDS)

Zinc: health effects and research priorities for the 1990s

This review critically summarizes the literature on the spectrum of health effects of zinc status, ranging from symptoms of zinc deficiency to excess exposure. Studies on zinc intake are reviewed in relation to optimum requirements as a function of age and sex. Current knowledge on the biochemical properties of zinc which are critical to the essential role of this metal in biological systems is summarized. Dietary and physiological factors influencing the bioavailability and utilization of zinc are considered with special attention to interactions with iron and copper status. The effects of zinc deficiency and toxicity are reviewed with respect to specific organs, immunological and reproductive function, and genotoxicity and carcinogenicity. Finally, key questions are identified where research is needed, such as the risks to human health of altered environmental distribution of zinc, assessment of zinc status in humans, effects of zinc status in relation to other essential metals on immune function, reproduction, neurological function, and the cardiovascular system, and mechanistic studies to further elucidate the biological effects of zinc at the molecular level.

Proximal splenorenal shunts for extrahepatic portal venous obstruction in children

OBJECTIVE

The results of proximal splenorenal shunts done in children with extrahepatic portal venous obstruction were evaluated.

SUMMARY BACKGROUND DATA

Extrahepatic portal venous obstruction, a common cause of portal hypertension in children in India, is being treated increasingly by endoscopic sclerotherapy instead of by proximal splenorenal shunt. It is believed that surgery (or the operation) carries high mortality and rebleeding rates and is followed by portosystemic encephalopathy and postsplenectomy sepsis. However, a proximal splenorenal shunt is a definitive procedure that may be more suitable for children, particularly those who have limited access to medical facilities and safe blood transfusion.

METHODS

Between 1976 and 1992, the authors performed 160 splenorenal shunts in children. Twenty were emergency procedures for uncontrollable bleeding and 140 were elective procedures--102 for recurrent bleeding and 38 for hypersplenism.

RESULTS

The overall operative mortality rate was 1.9%--10% (3/160-2/20) after emergency operations and 0.7% (1/140) after elective operations. Rebleeding occurred in 17 patients (11%), and pneumococcal meningitis developed in 1 patient who recovered later. Encephalopathy did not develop in any patient. Four patients died in the follow-up period--two of rebleeding, one of chronic renal failure and a subphrenic abscess, and one of unknown causes. The 15-year survival rate by life table analysis was 95%.

CONCLUSIONS

A proximal splenorenal shunt, a one-time procedure with a low mortality rate and good long-term results, is an effective treatment for children in India with extrahepatic portal venous obstruction.

Homeostasis of zinc in marginal human zinc deficiency: role of absorption and endogenous excretion of zinc

Although biochemical and immunologic aspects of mild or marginal human zinc deficiency have been well characterized, there is a paucity of data regarding the effects of prolonged marginal zinc deficiency on zinc homeostasis. It appears that human beings are able to maintain zinc homeostasis by increasing efficiency of zinc absorption and decreasing endogenous excretion of zinc when they are subjected to short-term dietary zinc restriction. However, a mild deficiency of zinc in human beings under usual circumstances is an outcome of chronic exposure to diets low in zinc lasting for many months and years. Therefore, it is important to determine whether or not the adapted zinc homeostasis during the short duration of dietary zinc deprivation is also maintained during a prolonged period of dietary zinc restriction. We assessed the efficiency of zinc absorption as well as endogenous zinc excretion during a 6-month period of dietary zinc restriction (63.1 mumol/day) in human volunteers by using a stable zinc (70Zn). Prolonged marginal zinc deficiency did not impair the functional role of endogenous zinc excretion in zinc homeostasis, but efficiency of zinc absorption was not sustained and decreased in the majority of our volunteers when the zinc-restricted diet was continued for 6 months. Such altered mechanisms of zinc homeostasis suggest that chronic human zinc deficiency warrants reassessment of dietary zinc requirement to preserve normal zinc status in the subsets of population that are vulnerable to zinc deficiency.

Zinc deficiency in elderly patients

Zinc is needed for growth and development, DNA synthesis, neurosensory functions, and cell-mediated immunity. Although zinc intake is reduced in elderly people, its deficiency and effects on cell-mediated immunity of the elderly have not been established. Subjects enrolled in "A Model Health Promotion and Intervention Program for Urban Middle Aged and Elderly Americans" were assessed for nutrition and zinc status. One hundred eighty healthy subjects were randomly selected for the study. Their mean dietary zinc intake was 9.06 mg/day, whereas the recommended dietary allowance is 15 mg/day. Plasma zinc was normal, but zinc in granulocytes and lymphocytes were decreased compared with younger control subjects. Of 118 elderly subjects in whom zinc levels in both granulocytes and lymphocytes were available, 36 had deficient levels. Plasma copper was increased, and interleukin 1 (IL-1) production was significantly decreased. Reduced response to the skin-test antigen panel and decreased taste acuity were observed. Thirteen elderly zinc-deficient subjects were supplemented with zinc, and various variables were assessed before and after zinc supplementation. Zinc supplementation corrected zinc deficiency and normalized plasma copper levels. Serum thymulin activity, IL-1 production, and lymphocyte ecto-5'-nucleotidase increased significantly after supplementation. Improvement in response to skin-test antigens and taste acuity was observed after zinc supplementation. A mild zinc deficiency appears to be a significant clinical problem in free-living elderly people.

Lower body negative pressure system for simulation of +Gz-induced physiological strain

Lower body negative pressure (LBNP) can be considered as an experimental substitute for the +Gz stress. In military aviation, pilots assume a near upright position and are subjected to +Gz stress in this position. An LBNP chamber has been developed in which negative pressure can be applied to the subject in the upright seated position. The chamber is easy to fabricate and can be used to assess the tolerance of subjects likely to be exposed to high levels of +Gz stress.

Ecto 5' nucleotidase (5'NT) as a sensitive indicator of human zinc deficiency

Ecto 5' nucleotidase (5'NT) is an integral plasma membrane enzyme located on most mammalian cells, and it is zinc dependent. We assayed 5'NT activity in the lymphocytes of two groups of subjects. The first group of six subjects had a mild state of zinc deficiency, as measured on the basis of zinc levels in lymphocytes, granulocytes, and platelets, but were otherwise healthy. They received 50 mg zinc as acetate orally for 12 weeks. The second six subjects were normal human volunteers in whom a mild state of zinc deficiency was induced experimentally by dietary techniques (4.2 to 5.6 mg daily zinc intake). For the assay of 5'NT, intact lymphocytes were incubated with 8-14C-labeled inosine monophosphate as substrate. Product and substrate were separated by thin-layer chromatography. Zinc level in cells was measured by flameless atomic absorption technique. In the first group of subjects with zinc deficiency, the decreased activity of 5'NT was corrected and the cellular zinc levels were normalized by oral zinc supplementation (p less than 0.01). In the second group of subjects, the baseline data were compared with those in early zinc depletion (4 to 8 weeks) and late depletion periods (greater than 20 weeks). A decrease in the activity of 5'NT was observed during the early zinc depletion phase. Zinc levels in lymphocytes, granulocytes, and platelets decreased significantly only during the late zinc depletion phase (p less than 0.01). Plasma zinc level did not change even during the late zinc depletion phase. Our studies show that 5'NT activity may be a sensitive and useful indicator of mild deficiency of zinc in human subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Discovery of human zinc deficiency and studies in an experimental human model

The importance of zinc for human health was first documented in 1963. During the past 25 y, deficiency of zinc in humans due to nutritional factors and several disease states has now been recognized. The high phytate content of cereal proteins is known to decrease the availability of zinc, thus the prevalence of zinc deficiency is likely to be high in a population consuming large quantities of cereal proteins. Alcoholism, malabsorption, sickle cell anemia, chronic renal disease, and chronically debilitating diseases are now known to be predisposing factors for zinc deficiency. A spectrum of clinical manifestations ranging from mild to severe degree have now been recognized in human zinc-deficiency states. Zinc is required for many biological functions including DNA synthesis, cell division, and gene expression. It is required for the activity of many enzymes in biological systems. Recent studies indicate that zinc is needed for cell-mediated immunity.

Pancreaticobiliary secretion of zinc and copper in normal persons and patients with Wilson's disease

The objectives of this study were (1) to examine basal and cholecystokinin-stimulated pancreaticobiliary secretion of zinc in normal subjects with zinc-adequate and zinc-deficient diets, and (2) to investigate whether basal and stimulated secretion of zinc was abnormal in patients with Wilson's disease before and after zinc therapy. Gastroduodenal intubation was performed in six healthy subjects and five patients with Wilson's disease. After intravenous infusion of octapeptide of cholecystokinin (40 ng/kg/hr) the pancreaticobiliary secretion of zinc increased from a basal rate of 283.1 +/- 75.8 nmol/L/min to a peak of 716.6 +/- 175.3 nmol/L/min in normal subjects. Normal subjects with a zinc-deficient diet had both lower basal (66.8 +/- 15.8 nmol/L/min) and stimulated (559.5 +/- 31 nmol/L/min) pancreaticobiliary secretion of zinc than with a zinc-sufficient diet. In contrast to the markedly reduced pancreaticobiliary secretion of copper, patients with Wilson's disease not treated with zinc had normal basal (226.6 +/- 126 nmol/L/min) and stimulated (728.7 +/- 195.5 nmol/L/min) zinc secretion. These studies indicate that a considerable amount of zinc is being secreted in pancreaticobiliary fluid in healthy subjects and there was no impairment of zinc secretion in patients with Wilson's disease. Our data also indicate that pancreaticobiliary secretion of zinc is dependent on the zinc status of the subjects, suggesting that endogenous secretion of zinc may play a significant role in the homeostasis of zinc.