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Biomedical subjects

Sajjad Ahmad

Publications and source records attributed to Sajjad Ahmad.

17 recordsLinked to original sources

Limiting youth access to tobacco: comparing the long-term health impacts of increasing cigarette excise taxes and raising the legal smoking age to 21 in the United States.

Although many states in the US have raised cigarette excise taxes in recent years, the size of these increases have been fairly modest (resulting in a 15% increase in the per pack purchase price), and their impact on adult smoking prevalence is likely insufficient to meet Healthy People 2010 objectives. This paper presents the results of a 75-year dynamic simulation model comparing the long-term health benefits to society of various levels of tax increase to a viable alternative: limiting youth access to cigarettes by raising the legal purchase age to 21. If youth smoking initiation is delayed as assumed in the model, increasing the smoking age would have a minimal immediate effect on adult smoking prevalence and population health, but would affect a large drop in youth smoking prevalence from 22% to under 9% for the 15-17-year-old age group in 7 years (by 2010)-better than the result of raising taxes to increase the purchase price of cigarettes by 100%. Reducing youth initiation by enforcing a higher smoking age would reduce adult smoking prevalence in the long-term (75 years in the future) to 13.6% (comparable to a 40% tax-induced price increase), and would produce a cumulative gain of 109 million QALYs (comparable to a 20% price increase). If the political climate continues to favor only moderate cigarette excise tax increases, raising the smoking age should be considered to reduce the health burden of smoking on society. The health benefits of large tax increases, however, would be greater and would accrue faster than raising the minimum legal purchase age for cigarettes.

Adult↗

Regulatory T cells and cytokines in malignant pleural effusions secondary to mesothelioma and carcinoma.

Immunotherapy against a variety of malignancies, including pleural-based malignancies, has shown promise in animal models and early human clinical trials, but successful efforts will need to address immunosuppressive factors of the tumor and host, particularly certain cytokines and CD4(+) CD25(+) regulatory T cells (Treg). Here, we evaluated the cellular and cytokine components of malignant pleural effusions from 44 patients with previously diagnosed mesothelioma, non-small cell lung cancer (NSCLC), or breast cancer and found significant differences in the immune profile of pleural effusions secondary to mesothelioma vs. carcinoma. Although a high prevalence of functionally suppressive CD4(+) CD25(+) T cells was found in carcinomatous pleural effusions, mesothelioma pleural effusions contained significantly fewer CD4(+) CD25(+) T cells. Activated CD8(+) T cells in pleural fluid were significantly more prevalent in mesothelioma than carcinoma. However, there is clear patient-to-patient variability and occasional mesothelioma patients with high percentages of CD4(+) CD25(+) pleural effusion T cells and low percentages of CD8(+) CD25(+) pleural effusion T cells can be identified. Mesothelioma pleural effusions contained the highest concentrations of the immunosuppressive cytokine transforming growth factor (TGF)-beta. Thus, the contribution of cellular and cytokine components of immunosuppression associated with malignant pleural effusions varies by tumor histology and by the individual patient. These results have implications for the development of immunotherapy directed to the malignant pleural space, and suggest the need to tailor immunotherapy to overcome immunosuppressive mechanisms in tumor environments.

Breast Neoplasms↗

Increasing excise taxes on cigarettes in California: a dynamic simulation of health and economic impacts.

BACKGROUND: California raised cigarette excise taxes in 1999, and may generate additional health and economic benefits by raising them further. METHODS: A dynamic computer simulation model follows births, deaths, migration, aging, and changes in smoking status for the entire population of California over 75 years to estimate the cumulative health and economic outcomes of these changes under several excise tax rate conditions (up to 100% price increase). RESULTS: A 20% tax-induced cigarette price increase would reduce smoking prevalence from 17% to 11.6% with large gains in cumulative life years (14 million) and QALY's (16 million) over 75 years. Total spending on cigarettes by consumers would increase by 270 million dollars in that span (all going to tax revenue), and those who reduce the number of years spent as a smoker would spend 12.5 billion dollars less on cigarettes. Total smoking-related medical costs would drop by 188 billion dollars. These benefits increase greatly with larger tax increases, with which tax revenues continue to rise even as smoking prevalence falls. CONCLUSIONS: Even considering benefits from the 1999 increase, California has not yet maximized the potential of excise taxes to lessen the negative impacts of smoking. Additional tax increases would provide added health benefits and revenue to the state.

California↗

Closing the youth access gap: the projected health benefits and cost savings of a national policy to raise the legal smoking age to 21 in the United States.

Current youth access laws, even if strictly enforced, do not prevent teenagers from obtaining cigarettes through social sources. To reduce the number of legal buyers a typical teenager routinely encounters, and to lessen ambiguity for vendors determining if a teen is of legal purchasing age, legislation raising the minimum legal purchase age (MLPA) for cigarettes to 21 has been discussed in several states. To estimate how a national law raising the smoking age to 21 would impact smoking prevalence, net costs (in terms of compliance enforcement, ID checking, and medical care) and health benefits (in terms of life years and QALYs) to the population over time, a dynamic computer simulation model was developed using publicly available secondary data. The model simulations were carried out for several scenarios assuming varying impacts of the policy change on smoking initiation probability over a 50-year period. One scenario assumes that smoking initiation probabilities for individuals under 21 shift by 3 years so a 18-year old in the simulation, for example, is as likely to initiate smoking as an 15-year old in the status quo. Under this assumption, raising the smoking age would reduce smoking prevalence for adults (age 18+) from the status quo level of 22.1-15.4% after 50 years. Prevalence would drop from 20 to 6.6% for 14-17-year olds, from 26.9 to 12.2% for 18-20-year olds, and from 21.8 to 15.5% for the 21+ group. The policy would produce a net cumulative savings to society of 212 billion US dollars (driven by reduced medical costs), and the accumulation of nearly 13 million additional QALYs over the period.

Adolescent↗

The AMA proposal to mandate nicotine reduction in cigarettes: a simulation of the population health impacts.

BACKGROUND: The American Medical Association (AMA) has advocated gradually reducing the nicotine content of cigarettes to decrease smoking prevalence. Some experts have voiced concerns that smokers may "compensate" by smoking more cigarettes or inhaling more deeply. Further, a black market may emerge, perpetuating cigarette availability. Thus, it is unclear whether a federal mandate would result in a net increase or decrease in population health. The purpose of this research is to estimate the long-term health gains or losses that are likely to accrue to the US population if the nicotine content of cigarettes is gradually reduced to trace levels over a 6-year period. METHODS: To estimate health impacts, we created the Tobacco Policy Model, a computer simulation model. The model simulates the US population as they age and change their smoking behavior over time. Secondary data for model parameters were obtained from publicly available sources. Population health impacts were measured as the change in cumulative quality-adjusted life-years (QALYs) in the US population over 50 years. RESULTS: Following a mandate to reduce nicotine, smoking prevalence is likely to decline from 23% to 5% of the population. Accordingly, a cumulative gain of 157 million QALYs is expected over 50 years. CONCLUSIONS: Despite any mortality increases due to compensatory smoking or the emergence of a black market, implementation of the AMA proposal would likely prevent the addiction of scores of new smokers and result in important gains to the nation's health. This research should prove useful to Congress as they contemplate giving the FDA the authority to regulate tobacco.

American Medical Association↗

Estimating the health impacts of tobacco harm reduction policies: a simulation modeling approach.

With adult smoking prevalence rates declining too slowly to reach national objectives, opinion leaders are considering policies to improve tobacco-related outcomes by regulating the composition of cigarettes to be (1) less harmful and/or (2) less addictive. Because harm reduction efforts may actually encourage higher cigarette consumption by promoting a safer image, and addictiveness reduction may increase the harmfulness of cigarettes by encouraging compensatory smoking behaviors, policymakers must consider the tradeoffs between these two approaches when proposing legislation to control cigarette content. To estimate health impacts, we developed a dynamic computer model simulating changes in the age- and gender-specific smoking behaviors of the U.S. population over time. Secondary data for model parameters were obtained from publicly available sources. Population health impacts were measured as change in smoking prevalence and the change in cumulative quality-adjusted life-years (QALYs) in the U.S. population over 75 years. According to the risk-use threshold matrix generated by the simulation, modifying cigarettes to reduce their harmfulness and/or addictiveness could result in important gains to the nation's health. Addictiveness reduction efforts producing a 60% improvement in smoking behavior change probabilities would produce a net gain in population health at every plausible level of increase of smoking-related harm that was modeled. A 40% reduction in smoking-related harm would produce a net QALY gain at every level of behavior change considered. This research should prove useful to policymakers as they contemplate giving the FDA the authority to regulate the composition of cigarettes.

Adult↗

Federal policy mandating safer cigarettes: a hypothetical simulation of the anticipated population health gains or losses.

If manufacturing a safer cigarette is technically possible--an open question--then mandating that tobacco manufacturers improve the safety of cigarettes would likely have both positive and negative implications for the nation's health. On the one hand, removing toxins may reduce the incidence of smoking-related diseases and premature mortality in smokers. On the other hand, smokers might be less inclined to quit, those who have quit might resume the habit, and youth who have never smoked will have one less reason to avoid tobacco use. To assess the expected population health impacts of a legislative or regulatory mandate, we created the Tobacco Policy Model, a system dynamics computer simulation model. The model relies on secondary data and simulates the U.S. population over time spans as long as 50 years. Our simulation results reveal that even if requiring cigarettes to be safer makes smoking more attractive and increases tobacco use, a net gain in population health is still possible.

Consumer Product Safety↗

Phenotypic characterization of murine primitive hematopoietic progenitor cells isolated on basis of aldehyde dehydrogenase activity.

There are several different technical approaches to the isolation of hematopoietic stem cells (HSCs) with long-term repopulating ability, but these have problems in terms of yield, complexity, or cell viability. Simpler strategies for HSC isolation are needed. We have enriched primitive hematopoietic progenitors from murine bone marrow of mice from different genetic backgrounds by lineage depletion followed by selection of cells with high aldehyde dehydrogenase activity using the Aldefluor reagent (BD Biosciences, Oxford, U.K.). Lin- ALDH(bright) cells comprised 26.8 +/- 1.0% of the total Lin- population of C57BL6 mice, and 23.5 +/- 1.0% of the Lin- population of BALB/c mice expressed certain cell-surface markers typical of primitive hematopoietic progenitors. In vitro hematopoietic progenitor function was substantially higher in the Lin- ALDH(bright) population compared with the Lin- ALDH(low) cells. These cells have higher telomerase activity and the lowest percentage of cells in S phase. These data strongly suggest that progenitor enrichment from Lin- cells on the basis of ALDH is a valid method whose simplicity of application makes it advantageous over conventional separations.

Animals↗

Derivation of human embryonic stem cells from day-8 blastocysts recovered after three-step in vitro culture.

Human embryonic stem cells (hESCs) have been derived from the inner cell mass (ICM) of day 5-7 blastocysts and hold great promise for research into human developmental biology and the development of cell therapies for the treatment of human diseases. We report here that our novel three-step culture conditions successfully support the development of day-8 human blastocysts, which possess significantly (p <.01) more ICM cells than day-6 blastocysts. Plating of ICMs isolated from day-8 blastocysts resulted in the formation of a colony with hESC morphology from which a new hESC line (hES-NCL1) was derived. Our stem cell line is characterized by the expression of specific cell surface and gene markers: GTCM-2, TG343, TRA1-60, SSEA-4, alkaline phosphatase, OCT-4, NANOG, and REX-1. Cytogenetic analysis of the hESCs revealed that hES-NCL1 line has a normal female (46, XX) karyotype. The pluripotency of the cell line was confirmed by the formation of teratomas after injection into severely combined immunodeficient mice and spontaneous differentiation under in vitro conditions.

Adult↗

Small bowel obstruction in children due to persimmon phytobezoars.

OBJECTIVE: To present the clinical picture of small bowel obstruction caused by Persimmon phytobezoars in children of Hazara (Northern Pakistan). DESIGN: Descriptive case series. PLACE AND DURATION OF STUDY: Three general surgical units of Ayub Teaching Hospital, Abbottabad from November 1998 to March 2003. PATIENTS AND METHODS: Nineteen children were managed for small bowel obstruction due to persimmon phytobezoars. The age, gender, season at the time of presentation, history of persimmon ingestion, symptoms, signs, site of obstruction, operative procedure and outcome were analyzed. RESULTS: There were 15 males and 4 females with ages ranging from 4-11 years (mean 7 years). All presented in winter with a positive history of persimmon ingestion. All had signs and symptoms and evidence of small bowel obstruction on plain abdominal x-rays. At laparotomy, ileum was the commonest site of obstruction. Milking of bezoars into caecum was performed in 17 patients while 2 patients required enterotomy for removal of bezoars. Complications occurred in 4 patients. There was no mortality. CONCLUSION: Small bowel obstruction in children due to persimmon phytobezoars is uncommon. However, it should be considered pre-operatively as a possible cause of intestinal obstruction in winter in children who have access to the fruit. Laparotomy should be performed for persistent obstruction or signs of strangulation.

Bezoars↗

Gastrointestinal perforation in children due to blunt abdominal trauma in Hazara, Northern Pakistan.

A retrospective study of 25 children with gastrointestinal perforation due to blunt abdominal trauma in a single region of Pakistan is presented. The age, sex, aetiology, site of perforation, abdominal and X-ray findings, associated injuries, surgical procedures and outcome were analysed. There were 20 boys and 5 girls: mean age was 10 years. The injuries were the result of road traffic accidents 12 (48%), falls 11 (44%) and 'struck by animals' two (8%). Associated injuries occurred in 19 (76%). On admission 20 (80%) patients had peritonitis while 18 (72%) had pneumoperitoneum. Mean time from trauma to admission was 10 hours and admission to operation was 5 hours. Ileum was the most common site of perforation. Simple closure was the most common surgical procedure. Complications occurred in nine (36%) patients--six (24%) died. Delay in presentation and operation was associated with increased morbidity and mortality. Frequent evaluation of the child and abdominal X-rays are still the important tools for early diagnosis of gastrointestinal perforation following blunt abdominal trauma.

Abdominal Injuries↗

catena-Poly[[tri-n-butyltin]-mu-N-(1-naphthyl)maleamato].

The crystal structure of catena-poly[[tri-n-butyltin]-mu-3-(1-naphthylaminocarbonyl)acrylato-kappa(2)O(1):O(3)], [Sn(C(4)H(9))(3)(C(14)H(10)NO(3))](n), is composed of polymeric chains wherein the metal center exhibits a distorted trigonal-bipyramidal geometry, with three n-butyl groups defining the trigonal plane [mean Sn[bond]C 2.133 (7) A] and the axial positions being occupied by the carboxylate O atoms of two different N-(1-naphthyl)maleamate ligands with inequivalent Sn[bond]O distances [2.167 (4) and 2.457 (4) A]. The N-(1-naphthyl)maleamate fragment forms an essentially planar seven-membered ring involving an intramolecular N[bond]H...O hydrogen bond.

Journal Article↗

The cost-effectiveness of raising the legal smoking age in California.

Given evidence that most smokers start smoking before the age of 18 and that smokers who start earlier in life are less likely to quit, policies that reduce or delay initiation could have a large impact on public health. Raising the legal minimum purchase age of cigarettes to 21 may be an effective way for states to reduce youth smoking by making it harder for teens to buy cigarettes from stores and by reducing the number of legal buyers they encounter in their normal social circles. To inform the ongoing debate over this policy option in California, this study provides an evaluation of the cost-effectiveness of raising the state's legal smoking age to 21. Costs and benefits were estimated from a societal perspective using a dynamic computer simulation model that simulates changes to the California population in age, composition, and smoking behavior over time. Secondary data for model parameters were obtained from publicly available sources. Population health impacts were estimated in terms of smoking prevalence and the change in cumulative quality-adjusted life years (QALYs) to the California population over a 50-year period. Economic impacts were measured in monetary terms for medical cost savings, cost of law enforcement, and cost of checking identification. Compared to a status quo simulation, raising the smoking age to 21 would result in a drop in teen (ages 14-17) smoking prevalence from 13.3% to 2.4% (82% reduction). The policy would generate no net costs, in fact saving the state and its inhabitants a total of $24 billion over the next 50 years with a gain of 1.47 million QALYs compared to status quo. This research should prove useful to California's policy makers as they contemplate legislation to raise the state's legal smoking age.

Adolescent↗

An audit of patients' satisfaction after adult day-case surgery at Ayub Teaching Hospital, Abbottabad.

BACKGROUND: Day-case surgery has become an important component in the provision of surgical care in the Western countries. This study was done to introduce the concept of day-case surgery and assess the patients' satisfaction after day case general surgery in our set up with vast rural communities lacking medical facilities and no day-case surgery units in the hospitals. METHODS: All those patients suitable for day-case surgery and who accepted day-case surgery for general surgical procedures in General Surgical 'A' unit of Ayub Teaching Hospital, Abbottabad were interviewed after the operation on follow up visits. Questions were asked about their satisfaction with day-case surgery. If they were not satisfied, the reasons for dissatisfaction were noted. Direct admissions and re-admissions after day-case surgery were recorded. Any complications in the postoperative period were also noted. The patient's preference for a similar procedure as day-case in future was also recorded. RESULTS: There were 122 patients in this study. 60(49%) were operated under general anesthesia and 62(51%) under local anesthesia. Fourty Nine (40%) patients were satisfied while 73(60%) were not satisfied with day-case surgery. Six (5%) patients were admitted directly after day-case surgery while 7(5.7%) patients were admitted after discharge. Complications occurred in 41(33.6%) patients at home. Wound complications and pain were the most common morbidity encountered by the patients. Twenty eight (23%) patients contacted a hospital or a doctor in the early postoperative period. Sixty two (51%) patients would prefer operation as in-patient while 74 (60.6 %) would prefer an overnight stay after the operation next time. CONCLUSIONS: Patients' satisfaction with day-case surgery in Ayub Teaching Hospital is not high. Short-stay surgery would be more appropriate in our set up.

Ambulatory Surgical Procedures↗

Pattern of carcinoma of oral cavity reporting at dental department of Ayub medical college.

BACKGROUND: Carcinoma of oral cavity is amongst the first ten commonest malignancies in Pakistan. Districts of Hazara (NWFP) and Northern Areas of Pakistan are among the high risk. areas. Here we present a report of oral cancers received in this center over a period of 10 years. METHODDS: This clinicopathological study consists of cases of carcinoma of oral cavity presenting to dentistry department of Ayub Medical College Abbottabad during 1993-2003. All cases were clinically examined and provisionally diagnosed. Biopsy was taken from all the lesions and the tissues submitted to histopathology department of Ayub Medical College. RESULTS: There were 50 carcinoma cases in the study, including 30 (60%) males and 20 (40%) females. Among these, 47 (94%,) were diagnosed as squamous cell carcinomas, that consisted 30 (63.82 %) males and 17 (36.17%) females. The other 6 % lesions were histologically diagnosed as malignant melanoma, adenocarcinoma and acinar cell carcinoma. The age of squamous cell carcinoma cases was 41-71 years. The maximum number of squamous cell carcinomas (34%) effected buccal mucosa. The other common sites were lip (26%), tongue (21%) and gums (19%). CONCLUSION: The results of this study are comparable with other such studies done in Pakistan and else where in the world showing commonality of factors associated with the development of the disease in this region of the country, which necessitates a detailed prospective study.

Adult↗

Accuracy of surgeon-performed abdominal utrasound for gallstones.

BACKGROUND: Gallstone disease is common in Pakistan. It is primarily diagnosed by ultrasonography. which is traditionally done by radiologists. If surgeons could perform ultrasonography, it would enable early diagnosis in one-stop clinic. This study was done to evaluate the accuracy of surgeon-performed abdominal ultrasonography to detect gallstones. METHODS: This study was carried out at Surgical A and Surgical C units of Ayub Teaching Hospital, Abbottabad from July, 2000 to December, 2002. One hundred fourty two patients with signs and symptoms of gallstone disease who had ultrasonography performed by a surgeon. trained in ultrasonography were exclusively studied. These patients were referred for further scanning by the radiologists who were unaware of the surgeon's interpretation. The results of surgeon and radiologist performed ultrasonography were compared. RESULTS: The interpretation of surgeon-performed ultrasonography was correct in 100 patients and incorrect in 42 patients. There were 100 True Positive, 41 True Negative, One False Negative and Zero False Positive scans yielding 99%, Sensitivity, 100% Specificity and 99.3%, Accuracy. Sensitivity of surgeon-performed ultrasonography in detecting gallstones compared to operative findings was 100%. CONCLUSIONS: Abdominal ultrasonography performed by an ultrasonography trained surgeon can detect gallstones as accurately as by a radiologist.

Adult↗

Parathyroid carcinoma.

Parathyroid carcinoma is a very rare cause of primary hyperparathyroidism and these tumors are usually hyper-functioning as compared to other malignant endocrine tumors. Surgery is the only effective primary treatment. We report a patient, who presented with pathological fracture of femur, hypercalcemia, bilateral renal stones, markedly raised Parathormone levels and palpable mass in the neck. Parathyroid adenoma was initially diagnosed and localized at left lower gland by Sestamibi scan and ultrasonography. She underwent surgery and enlarged parathyroid gland was removed. Intra operatively there was no evidence of local invasion or lymph nodes involvement but biopsy report suggested malignancy.

Adenoma↗