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Biomedical subjects

J C Godfrey

Publications and source records attributed to J C Godfrey.

At least 19 recordsLinked to original sources
PubMed1997

Zinc-induced suppression of inflammation in the respiratory tract, caused by infection with human rhinovirus and other irritants.

Free ionic zinc (Zn2+) in saliva shortens duration and severity of common cold (CC) symptoms. It is proposed that Zn2+ complexes with proteins of critical nerve endings and surface proteins of human rhinovirus (HRV) (a) interrupt nerve impulses and (b) block docking of HRV on intercellular adhesion molecule-1 (ICAM-1) on somatic cells, thereby interrupting HRV infection. Since leukocyte function associated antigen-1 (LFA-1) binds leukocytes to cells through ICAM-1, initiating inflammation, Zn2+ is expected to block LFA-1/ICAM-1 binding and thereby suppress inflammation. This could explain reduction of inflammation experienced by persons taking zinc gluconate/glycine (ZGG) lozenges for CC. Allergic rhinitis (AR) and CC share many common symptoms, and ZGG also mitigates AR symptoms. Focal irritation, increased ICAM-1 expression, and recruitment of leukocytes to epithelial foci are the common elements. Zinc ions may be an important anti-inflammatory factor because they can block docking of both HRV and LFA-1 with ICAM-1.

Anti-Inflammatory Agents↗
PubMed1996

How does zinc modify the common cold? Clinical observations and implications regarding mechanisms of action.

Clinical studies have shown that ionic zinc (Zn2+) dissolved in the mouth shortened manifestations of the common cold significantly, by an unknown mechanism. The observed immediate effect on symptoms is consonant with osmotic transport of Zn2+, placing a temporary chemical clamp on critical nerves. It is proposed that transient elevation of Zn2+ concentration in and around the nasal cavity facilitates Zn2+ complexation with known intercellular adhesion molecule binding sites on rhinovirus surfaces which prevents rhinovirus binding to cells and interrupts infection. The crystallographically determined surface of rhinovirus-14 has been found to contain binding sites for at least 360 Zn2+. Such binding of Zn2+ would be stabilized by numerous histidine, methionine, tyrosine and carboxyl/carboxylate groups known to line the HRV-14 surface canyons. The resulting blockage of HRV docking with intercellular adhesion molecule binding sites is proposed to be responsible for the observed reduction of the duration of colds by statistically significant and clinically meaningful times.

Carrier Proteins↗
PubMed1996

Zinc for treating the common cold: review of all clinical trials since 1984.

All eight publications since 1984 that have reported a total of 10 clinical studies of the treatment of common colds with zinc are reviewed. The reasons for the puzzling mix of diametrically opposite results in these studies are elucidated and related to independent in vitro investigations. A theoretical framework is put forth that explains the beneficial effects of zinc and that has a solid foundation based on the known molecular structures of the surface of human rhinovirus and intercellular adhesion molecule-1, the docking point for human rhinovirus present on the surfaces of cells of the nasal epithelium. The results of clinical investigations and theory suggest that consistently beneficial therapeutic effects can be expected of zinc ions from zinc gluconate with glycine in lozenges prepared according to homeopathic principles and procedures. The latest study published used an "intent to treat" statistical model, and the highly beneficial effects of zinc found in that study could not be compared directly with results from any earlier studies. Raw data from that study were therefore reanalyzed on the basis of assessable patients, and the results show an even better effect and can be compared directly with earlier findings. No side effects or adverse experiences due to zinc that were serious, disturbing, or persistent were found in any of the 10 studies.

Adult↗
PubMed1992

Zinc(II) in saliva: determination of concentrations produced by different formulations of zinc gluconate lozenges containing common excipients.

A study of the pH of saliva produced by humans sucking hard candy lozenges containing zinc gluconate and citric acid demonstrated the probability that the formulation delivered an insignificant amount of the contained zinc as Zn2+. This could account for the negative results of several clinical studies of this lozenge and similar formulations as treatment for the common cold. Direct measurement of unbound Zn2+ in saliva from this and other zinc gluconate formulations was required to substantiate the inference from the pH study. A specific-ion-electrode assay method was developed. Using this method, it was found that saliva completely suppresses the ionization of zinc to free Zn2+ in the presence of citric acid or a 30-fold molar excess of mannitol plus sorbitol. Under the same conditions, however, the presence of an excess of glycine does not interfere with ionization to produce Zn2+. This finding supports the hypothesis that the positive clinical results of three studies were due to the use of formulations which release ionic zinc.

Excipients↗
PubMed1992

Zinc gluconate and the common cold: a controlled clinical study.

A report in 1984 on the success of zinc gluconate against common cold symptoms could not be confirmed in three subsequent studies, which are now known to have used formulations that inactivated zinc. A non-chelating formulation including glycine, which releases 93% of contained zinc into saliva, was tested in a randomized, placebo-controlled, double-blind trial in 73 young adults. Efficacy was recorded in symptom diaries using a symptom severity rating. Patients' symptoms first appeared 1.34 days prior to entry to the study in both groups. Disappearance of symptoms occurred after an additional 4.9 days for zinc-treated patients versus 6.1 days for placebo-treated patients. A difference was noted in the efficacy of treatment if it was started 1 day after symptom onset: cold duration was an additional 4.3 days in zinc-treated patients compared with 9.2 days for placebo-treated patients. Cough, nasal drainage and congestion were the symptoms most affected, and only mild side-effects were noted.

Adult↗
PubMed1989

Celiprolol in systemic hypertension.

The safety and efficacy of orally administered celiprolol, a new beta 1-selective adrenergic blocking drug with peripheral beta 2-agonist properties, were assessed in 91 patients with mild to moderate systemic hypertension (supine diastolic blood pressure [BP] 95 to 114 mm Hg without medication) using a placebo-controlled, double-blind, randomized, titration-to-effect study design. All patients received placebo for 4 weeks and were then randomized to receive placebo (n = 46) or once-daily celiprolol (n = 45), which was titrated every 2 weeks (200, 400, 600 mg/day) over a 6-week period to achieve a reduction in supine diastolic BP to less than or equal to 90 mm Hg. Plasma lipids and lipoproteins were also assessed at baseline, during placebo and after randomization to active therapy in a subgroup of patients. Compared with placebo, celiprolol reduced supine and standing BP (reduction of supine BP -0.4/-2.1 mm Hg with placebo, -5.7/-6.4 with celiprolol, p less than 0.05; reduction of standing BP -1.7/-1.0 with placebo, -7.2/-4.9 with celiprolol, p less than 0.05). Supine heart rate was reduced by 6.8 beats/min with celiprolol compared with 2.0 beats/min with placebo (p less than 0.05). No differences were seen when the effects of placebo and celiprolol on plasma lipoproteins were compared. Celiprolol is a safe, effective and well tolerated once-daily antihypertensive drug and has no detrimental effects on plasma lipids.

Antihypertensive Agents↗
PubMed1984

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. I.

Chlorthalidone 25 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 25 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reactions.

Adult↗
PubMed1984

The efficacy of a potassium-sparing combination of chlorthalidone and triamterene in the control of mild and moderate hypertension. II.

Chlorthalidone 50 mg/triamterene 50 mg in once-daily oral doses was as effective in reducing blood pressure as chlorthalidone 50 mg alone. The decrease in serum potassium was statistically significantly less with the combination than for chlorthalidone. There were no notable differences between the treatments in any other measure of laboratory safety or adverse reaction.

Adult↗
PubMed1984

Chlorthalidone-triamterene: a potassium-sparing diuretic combination for the treatment of oedema.

The efficacy of a once-daily combination of chlorthalidone 50 mg plus triamterene 50 mg or chlorthalidone 100 mg plus triamterene 100 mg was compared to that of chlorthalidone 50 mg or 100 mg. This double-blind study was carried out in eighty-eight patients over a treatment period of 12 weeks. All patients entered the active medication period of 12 weeks after a placebo run-in period of 3 to 7 days, during which pretibial or malleolar pitting oedema averaging 2 to 4 mm developed. All patients started at the lower doses, i.e. forty-one started on chlorthalidone 50 mg plus triamterene 50 mg and forty-seven started on chlorthalidone 50 mg. The protocol provided for doubling the dose (but not for reducing it thereafter) at any time during the 12-week period when control of oedema was deemed inadequate. Eight of the combination therapy patients and sixteen of those on chlorthalidone required the higher doses. By Week 12, 96% of the chlorthalidone plus triamterene patients and 100% of the chlorthalidone patients had shown a reduction of at least 2 mm in depth of pits, and 92% and 72%, respectively, had complete disappearance of oedema. The decreases in pitting oedema were paralleled by mean weight losses of 2.4 kg and 3.1 kg, respectively, for the combination treatment group and the chlorthalidone group. Average serum potassium levels throughout the 12-week treatment period were 3.70 mEq/L for the patients taking the combination compared to 3.41 mEq/L of those taking chlorthalidone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1983

Indapamide in the stepped-care treatment of obese hypertensive patients.

A double-blind study was carried out in obese patients with moderately severe hypertension to assess the efficacy and tolerability of 2.5 mg indapamide as a once-a-day Step 1 drug compared to 50 mg hydrochlorothiazide also as a once-a-day Step 1 drug; to assess the efficacy and tolerability of a fixed daily dose of 2.5 mg indapamide administered concomitantly with methyldopa starting at 500 mg daily; and to compare the findings of efficacy and tolerability of 2.5 mg indapamide daily with those of 50 mg hydrochlorothiazide daily as Step 1 agents when methyldopa is the Step 2 drug. Twenty-nine patients completed the study and were evaluated. Nine patients achieved the study criterion of reduction of average standing diastolic pressure to 90 mmHg or less when treated with Step 1 medication only. Twenty patients required the addition of methyldopa to their Step 1 medication: 10 patients took 2.5 mg indapamide with an average constant daily dose of 1100 mg methyldopa and 10 patients took 50 mg hydrochlorothiazide with an average constant daily dose of 1575 mg methyldopa to achieve blood pressure control. All groups had mean diastolic pressure controlled at or below the 90 mmHg criterion during the period of constant methyldopa dosage for those patients who required Step 2 therapy. There were no significant differences between groups with respect to diastolic pressure during the constant dosage period. The indapamide patients required significantly (p less than 0.05) less methyldopa than did the hydrochlorothiazide patients in order to maintain satisfactory control of diastolic blood pressure. The number of responders was greater in the 2.5 mg indapamide + methyldopa group than it was in the 50 mg hydrochlorothiazide + methyldopa group, and responses were achieved more rapidly in the former group than in the latter. Indapamide (2.5 mg per day) was effective and well tolerated when used alone or as Step 1 medication in combination with methyldopa as Step 2 medication, and it compared favourably in this regard with hydrochlorothiazide.

Adult↗
PubMed1970

Semisynthetic coumermycins: structure-activity relationships.

The relative antimicrobial activity of a large series of semisynthetic coumermycins has been determined. Most of the derivatives, which were 3-substituted-4-hydroxy-8-methyl-7-[3-O-(5-methyl-2-pyrrolylcarbonyl) noviosyloxy] coumarins, had an in vitro antibacterial spectrum similar to that of the parent compound, coumermycin A(1), but were generally less potent in minimal inhibitory concentration (MIC) tests. Derivatives with an alkylcarboxamido, arylcarboxamido, or arylsulfonamido group in the 3 position had considerably greater in vitro activity than those possessing an amino-, aryl-, or alkyureido substituent. Efficacy in Staphylcoccous aureus Smith infections of mice was greater for those compounds with branched-chain alkylcarboxamido, unsubstituted, mono- or disubstituted aryl- and heteroaryl-carboxamido groups than for derivatives having an n-alkylcarboxamido, aralkyl-carboxamido, arylsulfonamido, or trisubstituted arylcarboxamido substituent. Significant in vitro activity against Klebsiella pneumoniae and other gram-negative species was restricted to those compounds having a 3-(3-n-alkyl-4-hydroxy-phenyl-carboxamido) group. Only the n-hexyl homologue demonstrated in vivo activity in a K. pneumoniae infection. Many derivatives were two- to threefold more active than coumermycin A(1) in orally treated mouse infections, despite the fact that their MIC values were considerably higher. This result was undoubtedly a reflection of the markedly greater oral absorbability possessed by many of the derivatives. Although peak oral mouse blood levels of some compounds were > 25 times higher than those of coumermycin A(1), their toxicity for the host was no greater. In addition, the semisynthetic coumermycins caused much less local irritation than coumermycin A(1) when administered parenterally.

Animals↗